99m Technetium-HMPAO-labeled platelet scan in practice: Preparation, quality control, and biodistribution studies

Abstract There is no biodistribution or imaging data on 99mtechnetium (Tc)-hexamethyl propylamine oxime (HMPAO)-labeled platelets in the literature. The current study aimed to present updated information about the clinical procedures for preparation and use of labeled platelets. Following two-step centrifugation at 1500 and 2500 rpm, the platelets were extracted from whole blood into platelet-rich plasma (PRP) above the buffy coat and then from PRP into a platelet pellet at the bottom of the tube. The 99mTc-HMPAO-labeled platelets were inspected for purity, viability, release of 99mTc from platelets, and sterility. Also, microscopic examination and thin layer chromatography (TLC) were performed. Biodistribution was assessed following necropsy in BALB/c mice and through imaging of New Zealand rabbits. The separation ratio was estimated at 98%, and radiochemical purity was measured to be 80%. The labeling efficiency was above 30% in more than half of the assays (range: 17-43%). The release of 99mTc from platelets was 9% per hour at 37ºC. After 24 hours, stability was estimated at 54% in the human serum. The target organs of mice included the spleen and liver. In rabbits, the imaging results indicated liver as the target organ. Thyroid uptake was negligible up to 90 minutes. Based on the findings, extraction of platelets and labeling them with 99mTc-HMPAO is a feasible and safe approach in routine practice.

Clinical Usefulness of 99mTc-Hexamethyl Propylene Amine Oxime Perfusion Single Photon Emission Computed Tomography for Early Phase Multiple System Atrophy

BACKGROUND: Clinical diagnosis of multiple system atrophy (MSA) relays on signs and symptoms that are often difficult to identify particularly at early stage. Indeed neuropathological studies have demonstrated that Parkinson variant of MSA (MSA-P) is the first cause of misdiagnosis in a cohort of patients presenting with parkinsonian features. But accurate diagnosis of these disorders is important for deciding on treatment, appropriate advice and prognosis since atypical parkinsonian disorders are characterized by poor response to dopaminergic treatment and more rapid disease progression. Therefore, we conducted this study to investigate difference of perfusion Single Photon Emission Computed Tomography (SPECT) in patients with the early phase of MSA-P using SPM program. METHODS: We recruited consecutively 21 patients with MSA-P and 48 age-matched healthy controls. All subjects underwent Tc-99m HMPAO perfusion SPECT and this perfusion images were analyzed. RESULTS: For MSA-P, only hypoperfusion was seen in the middle frontal gyrus of left frontal lobe, superior frontal gyrus of right frontal lobe, precentral gyrus of left frontal lobe, middle frontal gyrus of right frontal lobe and precentral gyrus of right frontal lobe with respect to healthy subjects. CONCLUSIONS: We cautiously assume that perfusion SPECT may offer significant advantages compared to other imaging techniques in the assessment of neuronal degeneration in MSA-P and may help the clinician in the diagnostic characterization of patients presenting with atypical parkinsonism.

Regional Cerebral Perfusion Abnormalities in Autistic Disorder: Statistical Parametric Mapping Analysis

OBJECTIVES: Autism is a well-known psychiatric disorder that is presumed to have a neural basis. To investigate the underlying neurofunctional abnormalities of autism, the authors performed single photon emission computed tomography (SPECT) on children with autism. METHODS: Fifty-five children with untreated autism (47 boys and 8 girls, mean age=50.6+/-20.28 months) were selected from among the patients visiting the child and adolescent psychiatric clinic of Seoul National University Hospital. Psychiatrists had diagnosed the participants according to the DSM-IV criteria for autistic disorder and the Childhood Autism Rating Scale (CARS) criteria for a diagnosis of autism. All participants were examined using 99mTC-HMPAO Brain SPECT. Using statistical parametric mapping (SPM) analysis, we compared the participants' SPECT images to standardized SPECT images of normal children, which had been retrospectively selected by the authors, on a voxel by voxel basis. Voxels with a p-value less than .001 were considered to be significantly different. RESULTS: The autistic group showed significant hypoperfusion in the right medial frontal gyrus, right precentral gyrus, and left precuneus gyrus. In addition, they showed no significant hyperperfusion areas when compared to the control group. CONCLUSION: The findings of hypoperfusion in the medial-frontal lobe and precuneus are accord with hemodynamic abnormalities that have been already reported. Therefore, these findings are compatible with the recently suggested "theory of mind" hypothesis and the disturbances in attention shifting that have been observed in autistic children.

Incidental Detection of a Pseudoaneurysm at an Amputation Stump in a Tc-99m HMPAO Labeled Leukocyte Scan / 핵의학분자영상

A 20-year-old man underwent a Tc-99m HMPAO labeled leukocyte scan for the evaluation of an infection at the stump of an AK amputation, which was conducted due to an open communicated fracture of the left lower leg. Blood-flow and blood-pool images demonstrated a pseudoaneurysm with a focus of intense activity medial to the stump, and centered within a large photopenic defect by surrounding hematoma. Delayed image obtained at 3 hours post-injection showed persistent intense and slight increased activity. Contrast angiography confirmed the presence of a pseudoaneurysm arising from a branch of the left superficial femoral artery.

Differences of Tc-99m HMPAO SPECT Imaging in the Early Stage of Subcortical Vascular Dementia Compared with Alzheimer's Disease / 핵의학분자영상

PURPOSE: The aim of this study is to assess the specific patterns of regional cerebral blood flow (rCBF) in patients with the early stage of subcortical vascular dementia (SVaD) and Alzheimer's disease (AD) using Tc-99m HMPAO SPECT, and to compare the differences between the two conditions. MATERIALS AND METHODS: Sixteen SVaD, 46 AD and 12 control subjects participated in this study. We included the patients with SVaD and AD according to NINCDS-ADRDA and NINDS-AIREN criteria. They were all matched for age, education and clinical dementia rating scores. Three groups were evaluated by Tc-99m HMPAO SPECT using statistical parametric mapping (SPM) for measuring rCBF. The SPECT data of patients with SVaD and AD were compared with those of normal control subjects and then compared with each other. RESULTS: SPM analysis of the SPECT image showed significant perfusion deficits on the right temporal region and thalamus, left insula and superior temporal gyrus, both cingulate gyri and frontal subgyri in patients with SVaD and on the left supramarginal gyrus, superior temporal gyrus, postcentral gyrus and inferior parietal lobule, right fugiform gyrus and both cingulate gyri in AD compared with control subjects (uncorrected p<0.01). SVaD patients revealed significant hypoperfusion in the right parahippocampal gyrus with cingulated gyrus, left insula and both frontal subgyral regions compared with AD (uncorrected p<0.01). CONCLUSION: Our study shows characteristic and different pattern of perfusion deficits in patients with SVaD and AD, and these results may be helpful to discriminate the two conditions in the early stage of illness.

Cerebral blood flow abnormalities in children with Sydenham's chorea: a SPECT study.

Functional imaging studies in patients with Sydenhams chorea have suggested brain perfusional abnormalities. In this study, we aimed to investigate the cerebral perfusion patterns of the cortical/subcortical structures by using Tc-99m hexamethylpropylenamine oxime single photon emission computed tomography in children with Sydenhams chorea, accompanied with magnetic resonance imaging and cranial Doppler studies. Brain MRI and Doppler studies of the all cases were normal. In the brain SPECT study, six patients were determined to have cerebral perfusion abnormalities. Although six patients responded well to the therapy, two girls who had hypoperfusion in the right frontal region as well as hypo- / hyperperfusion in the basal ganglia did not respond to therapy. While the chorea form of the patients who have cerebral perfusional abnormality was generalized, the clinical picture of the patients with normal cerebral perfusion was in the form of hemichorea.

A Case of Actinobacillus actinomycetemcomitans Bacteremia Associated with Permanent Pacemaker Lead Infection / 감염과화학요법

A 73-year-old man was admitted for intermittent episodes of fever and chills for 3 months. He had been implanted with a permanent pacemaker to control tachy-bradycardia syndrome 7 months before admission. Blood cultures were positive for Actinobacillus actinomycetemcomitans and a 99mTc-hexamethylpropylene amine oxime (99mTc-HMPAO) WBC scan revealed inflammation on the pacemaker lead in extracardiac site. Oral examination revealed several dental caries. The patient was treated with intravenous ceftriaxone, followed by oral ciprofloxacin without removal of the infected pacemaker lead. He was doing well 10 months without febrile episodes after discontinuation of antibiotics. This report describes the first case of A. actinomycetemcomitans bacteremia associated with a pacemaker lead and localized by 99mTc-HMPAO WBC scan

A Case of Actinobacillus actinomycetemcomitans Bacteremia Associated with Permanent Pacemaker Lead Infection / 감염과화학요법

A 73-year-old man was admitted for intermittent episodes of fever and chills for 3 months. He had been implanted with a permanent pacemaker to control tachy-bradycardia syndrome 7 months before admission. Blood cultures were positive for Actinobacillus actinomycetemcomitans and a 99mTc-hexamethylpropylene amine oxime (99mTc-HMPAO) WBC scan revealed inflammation on the pacemaker lead in extracardiac site. Oral examination revealed several dental caries. The patient was treated with intravenous ceftriaxone, followed by oral ciprofloxacin without removal of the infected pacemaker lead. He was doing well 10 months without febrile episodes after discontinuation of antibiotics. This report describes the first case of A. actinomycetemcomitans bacteremia associated with a pacemaker lead and localized by 99mTc-HMPAO WBC scan

A Case of Aorto-femoral bypass Graft Infection Complicated with Infective Endocarditis / 감염과화학요법

Prosthetic vascular graft infection (PVGI) is a relatively uncommon complication of peripheral vascular surgery and although rare, is the most severe complication in reconstructive vascular surgery. The early diagnosis of this complication can reduce the mortality. We report a case of aorto-femoral bypass graft infection, which was diagnosed by Tc-99m HMPAO WBC scan, complicated with infective endocarditis. A 60-year-old man had been operated with aortofemoral bypass graft because of aortojejunal fistula due to abdominal aortic aneurysm. Nine months later, he was admitted with fever of two months' duration. On echocardiolography, aortic regurgitation and vegetation were observed, and then he was diagosed with infective endocarditis. He was treated with antibiotics for 6 weeks. Recurrent bacteremia of unknown origin persisted despite antibiotic therapy. Multiple microorganisms were separately isolated from the blood cultures. He complained of intermittent right groin pain. Imaging study (CT, MRI, US) showed no definite evidence of graft infection. However, Tc-99m HMPAO WBC scan demonstrated uptake in the aortofemoral bypass graft site. The patient underwent emergent aortofemoral graft removal with axillobifemoral bypass and right femoropopliteal bypass.

A Case of Aorto-femoral bypass Graft Infection Complicated with Infective Endocarditis / 감염과화학요법

Prosthetic vascular graft infection (PVGI) is a relatively uncommon complication of peripheral vascular surgery and although rare, is the most severe complication in reconstructive vascular surgery. The early diagnosis of this complication can reduce the mortality. We report a case of aorto-femoral bypass graft infection, which was diagnosed by Tc-99m HMPAO WBC scan, complicated with infective endocarditis. A 60-year-old man had been operated with aortofemoral bypass graft because of aortojejunal fistula due to abdominal aortic aneurysm. Nine months later, he was admitted with fever of two months' duration. On echocardiolography, aortic regurgitation and vegetation were observed, and then he was diagosed with infective endocarditis. He was treated with antibiotics for 6 weeks. Recurrent bacteremia of unknown origin persisted despite antibiotic therapy. Multiple microorganisms were separately isolated from the blood cultures. He complained of intermittent right groin pain. Imaging study (CT, MRI, US) showed no definite evidence of graft infection. However, Tc-99m HMPAO WBC scan demonstrated uptake in the aortofemoral bypass graft site. The patient underwent emergent aortofemoral graft removal with axillobifemoral bypass and right femoropopliteal bypass.

Migration of 99mTc-Hexamethylpropylene Amine Oxime (HMPAO) Labeled Immature and Mature Dendritic Cells in the Mouse / 대한핵의학회잡지

PURPOSE: The purpose of this study is to evaluate migration of technetium-99m hexamethylpropylene amine oxime (99mTc-HMPAO) labeled immature and mature dendritic cells (DC) in the mouse. METHODS: DC were collected from bone marrow (BM) of tibiae and femurs of mice. Immature and mature DC from BM cells were radiolabeled with 99mTc-HMPAO. To evaluate the functional and phenotypic changes of DC from radiolabeling, the allogeneic mixed lymphocyte reaction (MLR) and fluorescence-activated cell sorting (FACS) analysis were performed before and after labeling with 99mTc-HMPAO. Migration of intravenously injected DC (iv-DC) was assessed by serial gamma camera images of mice with or without subcutaneous tumor. Percent injected dose per gram (%ID/g) was calculated in lungs, liver, spleen, kidneys, and tumor through dissection of each mice after 24 hours of injection. RESULTS: Labeling efficiency of immature and mature DC were 60.4 +/- 5.4% and 61.8 +/- 6.7%, respectively. Iv-DC initially appeared in the lungs, then redistributed mainly to liver and spleen. Migration of mature DC to spleen was significantly higher than that of immature DC (38.3 +/- 4.0 % vs. 32.2 +/- 4.1 % in control group, 40.4 +/- 4.1% vs. 35.9 +/- 3.8 % in tumor group; p< 0.05). Migration to tumor was also significantly higher in mature DC than in immature DC (2.4 +/- 0.3% vs 1.7 +/- 0.2%; p=0.034). CONCLUSION: Assessment of migration pattern of DC in mice was possible using 99mTc-HMPAO labeled immature and mature DC. Migration of mature DC to spleen and tumor was higher than that of immature DC when they were i.v. injected.

Pharmacotherapy and Regional Cerebral Blood Flow in Children with Obsessive Compulsive Disorder

While regional cerebral blood flow (rCBF) studies on adults involving the caudate, prefrontal, orbitofrontal, and cingulated areas have been reported, no such published data on children exist. In this study, we aimed to determine the significance of pre- and post-treatment regional cerebral blood flow (rCBF) differences in children with obsessive compulsive disorder (OCD) and compared them with healthy controls. Eighteen drug-free obsessive compulsive children, aged 11 to 15, without comorbid states except for anxiety disorders - participated in this study. The control group consisted of 12 children, aged 11 to 15, with no medical or psychiatric illnesses. Using SPECT (Single Photon Emission Computerized Tomography) scans with Technetium-99m-HMPAO-hexamethly propyleneamine oxime (Tc99mHMPAO), the rCBF was calculated in 15 regions of the control group according to a standard protocol, while in the study group, it was measured at baseline and after 12 weeks of treatment with a fixed dose of paroxetine (20 mg qd). We compared the resulting pre- and post-treatment CBF values for the control group and study group. The right and left caudates, right and left dorsolateral prefrontals, and cingulate had significantly higher rCBF in children with obsessive compulsive disorder than in the control group. These areas, in addition to the right anteromedial temporal, showed significant rCBF reduction after treatment with paroxetine. The mean percentage of change in obsession scores during the treatment correlated significantly with the baseline and post- treatment rCBF level of the right caudate, post-treatment left caudate, and baseline left caudate. Our findings on children are consistent with adult studies and support the theory of a cortical-striatal-thalamic-cortical loop disturbance in OCD.

A Novel Method of Brachytherapy Using Local Delivery of (99m) Tc-HMPAO for Coronary Stent Restenosis

BACKGROUND: Restenosis after percutaneous coronary intervention (PCI) is a matter that still remains to be resolved. Herein, the inhibitory effect of locally delivered (99m) Tc-HMPAO (hexamethyl propylene amine oxime) on neointimal hyperplasia after coronary stenting was examined in a pocine model, and its safety and efficacy observed in patients with coronary stent restenosis. METHODS: After a stent overdilation injury, local radioisotope delivery using (99m) Tc-HMPAO was applied to one coronary artery (Group I) and control therapy to another (Group II) in each of 10 pigs. Follow-up coronary angiogram (CAG) and histopathologic assessment were performed 4 weeks after stenting. Eleven patients (10 males and one female, 62.4 +/- 5.7 years of age) underwent local administration of 30 mCi/ 2 mL (99m) Tc-HMPAO shortly after PCI, via a Dispatch CatheterTM, followed by a whole body scan to evaluate the distribution of the (99m) Tc-HMPAO, as well as a thallium-201 (Tl-201) myocardial scan to evaluate myocardial perfusion. The major adverse cardiac events (MACE) were assessed during a one-year clinical follow-up. RESULTS: On histopathological analysis, the neointimal areas were 1.2 +/- 0.6 and 2.7 +/- 0.4 mm2 (p=0.002), and the histopathological areas of stenosis were 27.16.3 and 53.4 +/- 5.2% in Groups I and II (p=0.001), respectively. In the clinical study, there was no in-hospital MACE. On a quantitative coronary angiographic analysis, the minimal luminal diameter was increased from 0.4 +/- 0.3 to 2.9 +/- 0.2 mm, and diameter stenosis decreased from 84.2 +/- 9.5 to 16.3 +/- 11.0% following PCI. Follow-up CAG was performed in 9 cases (81.8%) and restenosis occurred in 2 (22.2%). On a follow-up CAG, the minimal luminal diameter, diameter stenosis rate, lumen loss and loss index were 2.0 +/- 0.8 mm, 27.7 +/- 2.9%, 0.7 +/- 0.7 mm and 0.2 +/- 0.3, respectively. During the one-year clinical follow-up there were no cases of death or acute MI, but two cases of target vessel revascularization (18.2%). CONCLUSION: Local delivery of (99m) Tc-HMPAO, a novel radiotherapy, can be used safely and effectively for coronary stent restenosis.

Effects of Hyperbaric Air Therapy on Cerebral Perfusion in Children with Cerebral Palsy

OBJECTIVE: To evaluate the effects of hyperbaric air therapy (HAT) on cerebral perfusion for children with cerebral palsy. METHOD: The protocol for HAT consisted of consecutive 10 days in which a child and his/her caregiver were held in 1.3 atm hyperbaric air chamber for 60 minutes per one day. Nine children with cerebral palsy underwent 99mTc-HMPAO single-photon emission computed tomography (SPECT) before and after HAT. The change of regional cerebral blood flow (rCBF) was evaluated by subtraction analysis using statistical parametric mapping. RESULTS: Average gestational age and birth weights were 34.0+/-5.1 months, and 2.3+/-1.2 kg, respectively. Two spastic quadriplegics, four spastic diplegics, two spastic hemiplegics, and one ataxic child were enrolled. In 3 out of 9 children, rCBF change was demonstrated; increased perfusion in right cerebellar hemisphere in child with diffuse brain atrophy and increased perfusion in diffuse cerebral cortex in child with left frontal leukoencephalopathy and decreased perfusion of right frontal cortex in child with right frontal leukoencephalopathy. CONCLUSION: These findings suggest that HAT may recruit less excitable neurons that was of functionally silent in motor cortex, previously. However, increased rCBF following HAT protocol could not be ruled out whether the result of learning effects or HAT.

Scintigraphic evaluation of disease activity in rheumatiod arthritis

This study was undertaken in a trial to assess the activity of RA in the Joints through using[99] Tc[m] HMPAO scintigraphy. Also, to investigate the repeatability of this technique and the correlation between the labeled white cell uptake, pain, inflammation and joint destruction. Twenty-nine RA patients were subjected to scanning on the first visit and 18 of them have been for a second visit. The score of pain and inflammation of the knee joint was rated using the visual analogue scale [VAS] of pain and inflammation by the patients. 99Tcm HMPAO labeled white cell uptake was estimated in each knee on both visits. The joint was measured on both imaging occasions. Joint destruction of the knee was measured by scoring the joint x-Ray using Larson's score. The data obtained were analyzed using the Pearson correlation analysis to estimate the correlation of the mean white cell uptake in the joints with other disease activity parameters are presented followed by the scatter plot of the mean white cell uptake in the joints against the significantly correlated variables. Pain correlated with objective measures of inflammation [labeled white cell uptake] and with the degree of joint destruction. There was no correlation with either x-ray scores or white cell uptake in the depressed patients

Evidence of cerebral hypoperfusion with [99m]tc HMPAO SPECT in Egyptian scleroderma patients

The aim of this study was to investigate regional cerebral blood flow [rCBF] with 99mTc-hexamethyl-propylenamine oxine [HMPAO] single photon emission computed tomography [SPECT] in a group of 22 patients affected with systemic sclerosis [SSc]. The SPECT findings were correlated with clinical data and MRI whenever possible. The study was conducted on 22 Egyptian SSc patients in comparison to ten healthy age-matched controls. Subjects affected with concomitant diseases that might interfere with the interpretation of the SPECT results were excluded. SPECT findings were correlated with clinical data, magnetic resonance imaging [MRI] of the brain and magnetic resonance angiography if available. Twelve SSc patients [54.5%] showed cerebral hypoperfusion, focal in 8 [66.7%] patients and diffuse hypoperfusion in 4 [33.3%] patients at the SPECT analysis. MRI was available in 15 patients and was shown to be altered in five of them [33.3%]. Magnetic resonance angiography [MRA] was normal in those five patients except one. No significant differences were found between the group of SSc patients showing hypoperfusion and those showing a normal SPECT scan regarding age, the duration of disease and damage of other organs typically involved in the disease. Focal or diffuse cerebral hypoperfusion was found with SPECT in more than half of the neurologically asymptomatic SSc patients. SPECT was more sensitive in reflecting changes of cerebral blood flow than MRI. The hypoperfusion was not linked to ageing and possibly reflects the cerebral location of the microangiopathic process characterizing the disease

A novel method of brachytherapy using local delivery of 99mTc-HMPAO for coronary stent restenosis / 대한내과학회지

BACKGROUND: Restenosis after percutaneous coronary intervention (PCI) still remains a matter to be solved. We examined the inhibitory effects of local delivery of 99mTc-HMPAO (hexamethylprophylene amine oxime), a radioisotope, on neointimal hyperplasia after coronary stenting through an animal experiment, and observed its safety and efficacy for the patients with coronary stent restenosis. METHODS: Stent overdilation injuries were performed in coronary arteries of 10 pigs. After stent overdilation injury, local radioisotope delivery using a 99mTc-HMPAO were performed in one coronary artery (Group I) and control therapy in another coronary artery in each pig (Group II). Follow-up coronary angiogram (CAG) and histopathologic assessment were performed at 4 weeks after stenting. Eleven patients (10 males, 62.4+/-5.7 years of age) underwent local administration of 30 mCi/ 2 mL of 99mTc-HMPAO shortly after PCI via Dispatch CatheterTM, and whole body bone scan and thallium-SPECT afterwards. Major adverse cardiac events (MACE) were assessed during one-year clinical follow-up. RESULTS: On histopathologic analysis, neointimal area was 1.2+/-0.6 mm2 in Group I and 2.7+/-0.4 mm2 in Group II (p=0.002), and histopathologic area stenosis was 27.1+/-6.3% in Group I, 53.4+/-5.2% in Group II (p=0.001). In clinical study, eleven patients with coronary in-stent restenosis were enrolled. There was no in-hospital MACE. On quantitative coronary angiographic analysis minimal luminal diameter and diameter stenosis increased from 0.4+/-0.3 mm and 84.2+/-9.5% to 2.9+/-0.2 mm and 16.3+/-11.0% after PCI, respectively. Follow-up CAG was performed in 9 cases (81.8%) and restenosis occurred in 2 cases (22.2%). On follow-up CAG minimal luminal diameter was 2.0+/-0.8 mm, diameter stenosis rate 27.7+/-2.9 %, lumen loss 0.7+/-0.7 mm and loss index 0.2+/-0.3. During one-year clinical follow-up there were no cases of death and acute MI, but two cases of target vessel revascularization (18.2%). CONCLUSION: Local delivery of 99mTc-HMPAO, one of the novel radiotherapies, can be used safely and effectively for coronary stent restenosis.

Strategic Infarct Dementia: Clinical Features, Neuroimaging and Neuropsychological Findings

BACKGROUND: Strategic infarct dementia (SID) is characterized by focal ischemic lesions involving specific sites that are critical for higher cortical functions. However, the mechanisms of SID are not well understood. We evaluated lesion sites, neuropsychiatric symptoms, neuroimaging and neuropsychological findings in patients with SID and have come up with suggestions of the mechanism behind SID. METHODS: Eleven patients with SID according to the NINDSAIREN criteria for vascular dementia were included. All patients were given a neurologic examination, brain MRI with MRA and brain perfusion SPECT using Tc-99m HMPAO. We evaluated neuropsychiatric symptoms and neuropsychological status using a Korean-version of the Neuropsychiatric Inventory(K-NPI) and Seoul Neuropsychological Screening Battery. RESULTS: Various sites were responsible for SID; the thalamus (n=5), genu of internal capsule (n=2), temporooccipital lobe (n=2), medial temporal lobe (n=1), medial frontal lobe (n=1). The most common neuropsychiatric symptom was apathy according to the K-NPI. Brain perfusion SPECT revealed ipsilateral cortical hypoperfusion, mainly in the frontal and temporal areas. In several cases, there were some degrees of cortical hypoperfusion in the contralateral areas of the lesion. On neuropsychological assessment, cognitive deficits on attention and frontal executive function were prominent. CONCLUSIONS: The thalamus, genu of internal capsule, and temporooccipital area were the most common sites responsible for SID. Based on the results that there were cortical hypoperfusion ipsilateral to subcortical strategic infarct and prominent cognitive deficits on attention and frontal executive function, it is suggested that disruption of the frontal-subcortical circuit may play an important role in patients with SID.

Clinical Features, Drug Responsiveness and Neuroimaging Findings in Dementia with Lewy Bodies

BACKGROUND: Dementia with Lewy bodies (DLB) is the second common degenerative dementia and has several characteristics including fluctuating cognition, visual hallucination and parkinsonism. We investigated clinical manifestations, responsiveness to drugs and neuroimaging findings in DLB patients. METHODS: Ten probable DLB patients were included in this study. For responsiveness to drugs, we measured Unified Parkinson's Disease Rating Scale (UPDRS) of rest tremor, rigidity and bradykinesia (finger tapping and leg agility), and Korean version of mini-mental state examination (K-MMSE) before and after administration of levodopa or cholinesterase inhibitors. Brain MRI, cerebral perfusion SPECT (Tc-99m HMPAO) and dopamine transporter SPECT (123I-IPT) were also performed. RESULTS: All patients were men and mean age of onset was 66.9 years (range from 58 to 80). All had fluctuating cognition and parkinsonism, and 7 had visual hallucination. Mean increment of K-MMSE after administration of cholinesterase inhibitors was 2.1 points. Levodopa reduced UPDRS scores of tremor, rigidity and bradykinesia by 0.4, 0.6 and 1.0 points, respectively. Cerebral perfusion SPECT using Tc-99m HMPAO showed hypoperfusion in occipital area as well as fronto-temporoparietal areas. Dopamine transporter SPECT using 123I-IPT revealed reduced uptake comparable to Parkinson's disease in the striatum. CONCLUSIONS: DLB should be first considered as one of possible diagnoses in patients showing dementia in the early stage of parkinsonism. Responsiveness of parkinsonism to levodopa seems favorable. Cholinesterase inhibitors are thought promising in enhancing cognition in short term periods. It is suggested that occipital hypoperfusion be a characteristic finding in DLB and be helpful in differentiating DLB from other degenerative dementias.

New Methods of Vascular Brachytherapy for Coronary Stent Restenosis

Over the last decade, stenting has emerged as the dominant form of percutaneous coronary intervention (PCI) and is currently performed in 80% of all PCIs. As a result, treatment of in-stent restenosis (ISR) has become an increasingly frequent challenge for the interventional cardiologist. Any anti-restenosis therapy under consideration must contend with the two basic mechanisms of vessel re-narrowing following coronary intervention: vascular contraction, which can be mechanically blocked with a typical balloon expandable stent; and neointimal proliferation, which is a complex cellular reaction to the injury caused by the actions of mechanical devices such as balloons, stents, and atherectomy catheters. Recently, several randomized clinical trials have demonstrated that intracoronary brachytherapy can substantially reduce the rates of both angiographic and clinical restenosis in patients undergoing PCI for ISR. Vascular radiotherapy is the first proven, clinically effective anti-restenosis therapy. Despite its established efficacy, there remains much room for improvement in the aspects of safety and cost effectiveness. We have developed novel methods of brachytherapy using local delivery of 99mTc-HMPAO and 166Ho-coated balloon, which are safe and effective in the prevention of coronary stent restenosis.