Unusual Case of Pseudomembranous Colitis Presenting as Fever of Unknown Origin Diagnosed by Tc-99m-HMPAO-labeled Leukocytes SPECT/CT.

The fever of unknown origin (FUO) represents a complex diagnostic challenge due to the wide range of etiologies that could cause it, including neoplastic, infectious, rheumatic/inflammatory, and miscellaneous disorders. Several nuclear medicine techniques have proven to be valuable tools for guiding etiologic diagnosis in the setting of FUO. One of these is technetium-99m (Tc-99m)-hexamethylpropylene amine oxime (HMPAO)-labeled leukocyte scintigraphy, which is a diagnosis method that allows in most cases the localization and evaluation of the extension of an occult infection. This paper presents an uncommon case of pseudomembranous colitis without diarrhea as etiology of FUO diagnosed by Tc-99m-HMPAO-labeled leukocytes.

Leukocyte Labeling with Tc-99m-HMPAO: The Role of Leucocyte Numbers and Medication on the Labeling Efficacy and Image Quality.

Objectives: The aim of this study is to evaluation of Tc-99m-hexamethylpropyleneamineoxime (HMPAO)-labeled leukocytes in terms of radiochemical, biochemical, and microbiological quality controls and to examine the effect of leukocyte numbers of the blood obtained from patients and the medications currently used by the patients on the radiochemical yields of Tc-99m-HMPAO-labeled leukocytes, and imaging quality was evaluated. Methods: Thirty paients were included in our study who applied to Istanbul University-Cerrahpasa, Cerrahpasa Faculty of Medicine, Department of Nuclear Medicine for Tc-99m-HMPAO-labeled leukocyte scintigraphy. Devices and chemicals used in the preparation of Tc-99m-HMPAO-labeled laukocytes were compared with other nuclear medicine clinics. Tc-99m-HMPAO-labeled leukocytes were evaluated in terms of radiochemical, biochemical, and microbiological quality controls. The effect of leukocyte numbers of the blood obtained from patients and the medications currently used by the patients on the radiochemical yields of Tc-99m-HMPAO-labeled leukocytes and imaging quality was evaluated. Results: The pH range of Tc-99m-HMPAO was 6-8 and the radiochemical purity was 90±2.04% (n=30), the radiochemical yield of Tc-99m-HMPAO-labeled leukocytes was 51±2.18% (n=30), the radiolabeling yield of Tc-99m-HMPAO-labeled leukocyte increased as the amount of white blood cell in the blood increased and whether the patients used any antibiotic, blood thinners, insulin and blood pressure medications did not affect the radiolabeling yield of Tc-99m-HMPAO-labeled leukocytes. The number of erythrocytes were removed at a rate of >99% in LPR by starch solution (6% HES; in the hemocytometric examination of Tc-99m-HMPAO-labeled leukocytes performed zeroth and 4th h, living/dead cell ratio was found 97.5% and the product was sterile. Conclusion: Tc-99m-HMPAO was labeled with leukocytes successfully, and Tc-99m-HMPAO-labeled leukocytes was safely injected to the patients as sterile without loss of vitality and aggregation.

Unexpected Detection of Abscessualized Lung Carcinoma on Tc-99m-HMPAO-labeled Leukocytes Scintigraphy Misdiagnosed on Chest Computed Tomography.

Technetium-99m (Tc-99m)-hexamethylpropylene amine oxime (HMPAO)-labeled leukocytes scintigraphy is well established for investigating and diagnosing infections in bone and soft tissue, as well as for the detection of occult infection. A 71-year-old female who was recently diagnosed with bronchopulmonary neuroendocrine tumor of the right lung was referred for an intermittent fever of unknown origin associated with chill at night for the last month. Chest computed tomography (CT) scan showed a thrombotic widespread of the superior vena cava and a solid pathological tissue in the superior segment of the inferior lobe of the right lung with consensual atelectasis. Being a carrier of port-a-cath, an infection of this device was suspected. Therefore, Tc-99m-HMPAO-labeled leukocytes single-photon emission computed tomography (SPECT) was performed, and matching pairs of CT scan and Tc-99m-HMPAO-labeled white blood cell SPECT images were fused. Through this means, it was found that the area of the radiotracer increased uptake corresponded with the soft tissue density mass detected by CT scan localized at the inferior lobe of the right lung. The hybrid SPECT/CT fused imaging was crucial for diagnosis of the presence of a lung abscess localized in correspondence with the known lung cancer region.

A Case of Habitual Neck Compression Induced Electroencephalogram Abnormalities: Differentiating from Epileptic Seizures Using a Tc-99m HMPAO SPECT.

Self-induced hypoxia has been reported particularly in adolescents, and it can result in neurological injury. Here, we present a case of electroencephalogram (EEG) abnormalities induced by habitual neck compression differentiated from epileptic seizures by Tc-99m HMPAO SPECT. A 19-year-old male was admitted for evaluation of recurrent generalized tonic-clonic seizures. No interictal EEG abnormality was detected; however, abnormal slow delta waves were found immediately after habitual right neck compression. To differentiate EEG abnormalities due to a hemodynamic deficit induced by habitual neck compression from an epileptic seizure, Tc-99m HMPAO SPECT was performed immediately after right carotid artery compression. Abnormal delta waves were triggered, and cerebral hypoperfusion in the right internal carotid artery territory was detected on Tc-99m HMPAO SPECT. The slow delta wave detected on the EEG resulted from the cerebral hypoperfusion because of the habitual neck compression.

Persistent migraine aura: new cases, a literature review, and ideas about pathophysiology.

BACKGROUND: Persistent migraine aura without infarction (PMA) is a rare condition that is defined as an aura that lasts longer than 1 week in absence of infarction. Two types of PMA have been distinguished, notably persistent primary visual disturbance (PPVD) and typical aura (TA). OBJECTIVES: This case-based review article describes four new cases of PMA as well as reviews all cases reported, trying to identify relevant associations, in particular with respect to functional investigations. METHODS: We performed a systematic literature search, extending from the period when it was first described (1991) to March 2014. We included all case descriptions of which criteria for PMA formulated in the International Classification of Headache Disorders, second edition, were met. In addition, we described four new cases. RESULTS: We identified 47 cases of PMA, 27 PMA-PPVD and 19 PMA-TA. In one case, there was not enough information to define the type of PMA. The mean age of onset was 30 years, varying from 7 to 74 years. The duration of symptoms varied from 9 days to 28 years. Besides a longer duration in symptoms in the PMA-PPVD group, we could not identify any differences between these groups. Some authors report occipital hypoactivity on Tc99m-hexamethylpropylene amine oxime -single-photon emission computed tomography (Tc99m-HMPAO-SPECT) or fluorodeoxyglucose-positron emission tomography (FDG-PET) in PMA cases, but data are inconsistent. Multiple drugs have been used for the treatment of PMA, usually with little effect. Lamotrigine seems to be the most effective drug. CONCLUSION: Despite the fact that 47 cases of PMA have been reviewed in this paper, many questions remain. The cases that have been described so far show inconsistent data with respect to the results of functional studies as well as treatment effects. The pathophysiology of PMA is still largely a matter of conjecture.

Brain MRI, Tc-99m HMPAO SPECT and F-18 FP-CIT PET/CT Findings in a Patient with Wilson Disease: A Case Report.

A 34-year-old female had experienced head and hand tremors with a dystonic component for 8 months. Brain MRI showed T2 high signal intensity in the periaqueductal region, dorsal midbrain and dorsal upper pons. No abnormal uptake was noted on Tc-99m HMPAO SPECT or F-18 FP-CIT PET/CT. Wilson disease was diagnosed according to the 2008 consensus guideline from the American Association for the Study of Liver Disease and 2012 guideline from the European Association for the Study of the Liver. This case demonstrates T2 signal change in the basal ganglia, excluding the putamen, in a Wilson disease patient with relatively severe clinical findings, but normal Tc-99m HMPAO SPECT and F-18 FP-CIT PET/CT.

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.

The Additional Value of Tc 99m HMPAO White Blood Cell SPECT in the Evaluation of Bone and Soft Tissue Infections.

OBJECTIVE: The aim of this prospective study was to evaluate the additional value of Tc 99m HMPAO white blood cell (WBC) SPECT for bone and soft tissue infections. MATERIALS AND METHODS: Thirty-eight patients with suspected bone and joint infection were included in the study. Patients were assigned into 2 groups according to the presence of orthopedic implants. All patients had multiphase bone scan (BS) with Tc 99m methylene diphosphonate and WBC scintigraphy. The planar images of BS and WBC images were evaluated together. SPECT WBC images were evaluated separately. RESULTS: Group 1 had 30 patients including 12 patients with diabetic foot, 17 patients with suspected relapse of chronic osteomyelitis and 1 with septic arthritis. In 19 of 30 patients, BS and planar WBC images were similar with SPECT images in terms of final diagnosis. In the remaining 11 patients, planar BS+planar WBC images and SPECT WBC images were discordant. Group 2 included 8 patients with suspected infection of orthopedic implants. There was no difference between planar BS+planar WBC images and SPECT WBC in 6 of 8 patients. SPECT WBC images changed the diagnosis of 13 (34.2%) patients in the whole group. SPECT WBC images did not have any contribution in the evaluation of the 6 patients who had reactive changes. CONCLUSION: SPECT images made significant contribution in discriminating soft tissue infection from osteomyelitis and improved diagnosis in terms of localization and the extent of disease. CONFLICT OF INTEREST: None declared.

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.

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.

Tc-99m HMPAO Brain Perfusion SPECT Findings in Acute Cerebellitis

Acute cerebellitis is an uncommon neurological complication that may occur following childhood viral infections, and is rarely reported in adults. Imaging studies show no abnormalities in the majority of cases. We experienced three cases of acute cerebellitis, which showed no abnormal findings on MRI, but revealed diffusely increased cerebellar per-fusions on brain perfusion SPECT, which normalized 5~6 months later. Therefore, brain perfusion SPECT is consid-ered to be useful in identifying acute cerebellitis and in monitoring its clinical course.

Crossed Cerebellar Hyperperfusion on Ictal Tc-99m HMPAO Brain SPECT: Clinical Significance for Differentiation of Mesial or Lateral Temporal Lobe Epilepsy and Related Factors for Development / 대한핵의학회잡지

PURPOSE: The aim of this study was to determine whether crossed cerebellar hyperperfusion (CCH) was helpful in discriminating mesial from lateral temporal lobe epilepsy (TLE) and what other factors were related in the development of CCH on ictal brain SPECT. MATERALS AND METHODS: We conducted retrospective analysis in 59 patients with TLE (M:41, F:18; 27.4+/-7.8 years old; mesial TLE: 51, lateral TLE: 8), which was confirmed by invasive EEG and surgical outcome (Engel class I , II). All the patients underwent ictal Tc-99m HMPAO brain SPECT and their injection time from ictal EEG onset on video EEG monitoring ranged from 11 sec to 75 sec (32.6+/-19.5 sec) in 39 patients. Multiple factors including age, TLE subtype (mesial TLE or lateral TLE), propagation pattern (hyperperfusion localized to temporal lobes, spread to adjacent lobes or contralateral hemisphere) and injection time were evaluated for their relationship with CCH using multiple logistic regression analysis RESULTS: CCH was observed in 18 among 59 patients. CCH developed in 29% (15/51) of mesial TLE patients and 38% (3/8) of lateral TLE patients. CCH was associated with propagation pattern; no CCH (0/13) in patients with hyperperfusion localized to temporal lobe, 30% (7/23) in patients with propagation to adjacent lobes, 48% (11/23) to contralateral hemisphere. Multiple logistic regression analysis revealed that propagation pattern (p=0.01) and age (p=0.02) were related to the development of CCH. CONCLUSION: Crossed cerebellar hyperperfusio ictal brain SPECT did not help differentiate mesial from lateral temporal lobe epilepsy. Crossed cerebellar hyperperfusion was associated with propagation pattern of temporal lobe epilepsy and age.

Quantification of Cerebrovascular Reserve Using Tc-99m HMPAO Brain SPECT and Lassen's Algorithm / 대한핵의학회잡지

PURPOSE: For quantitative estimation of cerebrovascular reserve (CVR), we estimated the cerebral blood flow (CBF) using Lassen's nonlinearity correction algorithm and Tc-99m HMPAO brain SPECT images acquired with consecutive acquisition protocol. Using the values of CBF in basal and acetazolamide (ACZ) stress states, CBF increase was calculated. MATERALS AND METHODS: In 9 normal subjects (age: 72+/-4 years), brain SPECT was performed at basal and ACZ stress states consecutively after injection of 555 MBq and 1,110 MBq of Tc-99m HMPAO, respectively. Cerebellum was automatically extracted as reference region on basal SPECT image using threshold method. Assuming basal CBF of cerebellum as 55 ml/100 g/min, CBF was calculated for every pixel at basal states using Lassen's algorithm. Cerebellar blood flow at stress was estimated comparing counts of cerebellum at rest and ACZ stress and Lassen's algorithm. CBF of every pixel at ACZ stress state was calculated using Lassen's algorithm and ACZ cerebellar count. CVR was calculated by subtracting basal CBF from ACZ stress CBF for every pixel. The percent CVR was calculated by dividing CVR by basal CBF. The CBF and percentage CVR parametric images were generated. RESULTS: The CBF and percentage CVR parametric images were obtained successfully in all the subjects. Global mean CBF were 49.6+/-5.5 ml/100g/min and 64.4+/-10.2 ml/100g/min at basal and ACZ stress states, respectively. The increase of CBF at ACZ stress state was 14.7+/-9.6 ml/100g/min. The global mean percent CVR was 30.7% and was higher than the 13.8% calculated using count images. CONCLUSION: The blood flow at basal and ACZ stress states and cerebrovascular reserve were estimated using basal/ACZ Tc-99m-HMPAO SPECT images and Lassen's algorithm. Using these values, parametric images for blood flow and cerebrovascular reserve were generated.

Tc-99m HMPAO White Blood Cell Scintigraphy of an Enterovesical Fistula Complicating Crohn's Disease / 대한핵의학회잡지

Computed tomography (CT) seems to be the best imaging modality to diagnose an enterovesical fistula, but is not always able to demonstrate enterovesical fistula itself. In this case report, we present Tc-99m HMPAO white blood cell (WBC) scintigraphic findings of an enterovesical fistula complicating Crohn's disease. A 22 year-old male presented with a one-month history of urinary symptoms such as dysuria, hematuria, and frequency. The patient had intermittent right lower quadrant pain, diarrhea and hematochezia. Enterovesical fistula was highly suggestive in pelvic CT which showed air density in the urinary bladder, but cystoscopy failed to find an opening of the fistula. Tc-99m HMPAO WBC scintigraphy for evaluation of inflammatory bowel disease incidentally demonstrated enterovesical fistular tract. Crohn's disease was later confirmed by histologic examination of the surgical specimen. In our patient, Tc-99m HMPAO WBC imaging was helpful in determining the location of the fistula as well as assessing the disease activity and extent of the Crohn's disease.

Alterations of Cerebral Blood Flow and Cerebrovascular Reserve in Patients with Chronic Traumatic Brain Injury Accompanying Deteriorated Intelligence / 대한핵의학회잡지

PURPOSE: The purpose of this study was to evaluate alterations of regional cerebral blood flow (CBF) and cerebrovascular reserve (CVR), and correlation between these alternations and cognitive dysfunction in patients with chronic traumatic brain injury (TRI) and normal brain MRI findings. MATERIALS AND METHODS: Thirty TBI patients and 19 healthy volunteers underwen1 rest/acerazolamide brain SPECT using Tc-99m HMPAO. Korean-Wechsler Adult Intelligence scale test was also performed in the patient group. Statistical analysis was performed with statistical parametric mapping software (SPM97), RESULTS: CBF was diminished in the left hemisphere including Wernicke's area in all patients with lower verbal scale scores. In addition, a reduction in CBF in the right frontal, temporal and parietal cortices was related with depressed scores in information, digital span, arithmetic and similarities, In patients with lower performance scale scores. CBF was mainly diminished in the right hemisphere including superior temporal and supramarginal gyri, premotor, primary somatomotor and a port of prefrontal cortices, left frontal lobe and supramarginal gyrus. CVR was diminished in sixty-four Brodmann's areas compared to control. A reduction in CVR was demonstrated bilaterally in the frontal and temporal Iobes in patients with lower scores in both verbal and performance tests, and in addition, both inferior parietal and occipital lobes in information subset. CONCLUSION: Alterations of CBF and CVR were demonstrated in the symptomatic TBI patients with normal MRI finding. These alterations were correlated with the change of intelligence, of which the complex functions are subserved by multiple interconnected cortical structures.

Usefulness of Brain Tc-99m HMPAO SPECT in Establishing Lateralization of Intractable Seizure in Children

PURPOSE: To determine the role of Tc-99m HMPAO SPECT imaging in children with intractable seizure by evaluating the interictal period. METHODS: We compared the EEG, CT and MRI medical records with those of Tc-99m HMPAO SPECT in 42 patients with intractable seizure referred to Kyunghee University Hospital, from April 1983 to September 1998, retrospectively. RESULTS: Mean age was 8.3 years and male to female ratio was 2.5 : 1. Multiple surface EEG recordings were performed in 42 patients and EEG findings of all patients showed an epileptogenic focus, with the most common area of abnormal findings being the Lt. sides. Brain CT was performed in 23 out of 42 patients(54.8%), and 15 out of the 23 patients(65.2%) showed abnormal findings and the most common area of abnormal findings were both sides. Brain MRI was performed in 21 out of 42 patients(50.0%), and 14 of the 21 patients(66.6%) showed abnormalities and the most common area of abnormal findings were both sides. In 32 out of the 42 patients (76.2%), SPECT images showed abnormal cerebral perfusion, most common area of hypoperfusion were Lt. sides. In 10 out of 14 cases, there were lateralizing abnormalities on the same side shown in SPECT and EEG, CT or MRI findings. CONCLUSION: We concluded that Tc-99m HMPAO SPECT seemed to be a useful tool in the evaluation of intractable seizure patients.

Usefulness of Brain Tc-99m HMPAO SPECT in Establishing Lateralization of Intractable Seizure in Children

PURPOSE: To determine the role of Tc-99m HMPAO SPECT imaging in children with intractable seizure by evaluating the interictal period. METHODS: We compared the EEG, CT and MRI medical records with those of Tc-99m HMPAO SPECT in 42 patients with intractable seizure referred to Kyunghee University Hospital, from April 1983 to September 1998, retrospectively. RESULTS: Mean age was 8.3 years and male to female ratio was 2.5 : 1. Multiple surface EEG recordings were performed in 42 patients and EEG findings of all patients showed an epileptogenic focus, with the most common area of abnormal findings being the Lt. sides. Brain CT was performed in 23 out of 42 patients(54.8%), and 15 out of the 23 patients(65.2%) showed abnormal findings and the most common area of abnormal findings were both sides. Brain MRI was performed in 21 out of 42 patients(50.0%), and 14 of the 21 patients(66.6%) showed abnormalities and the most common area of abnormal findings were both sides. In 32 out of the 42 patients (76.2%), SPECT images showed abnormal cerebral perfusion, most common area of hypoperfusion were Lt. sides. In 10 out of 14 cases, there were lateralizing abnormalities on the same side shown in SPECT and EEG, CT or MRI findings. CONCLUSION: We concluded that Tc-99m HMPAO SPECT seemed to be a useful tool in the evaluation of intractable seizure patients.

Change of Cerebral Blood Flow Distribution and Vascular Reserve according to Age in Koreans Measured by Tc-99m HMPAO Brain SPECT / 대한핵의학회잡지

PURPOSE: The aim of this study was to evaluate the normal values of regional cerebral blood flow (rCBF) and cerebrovascular reserve (CVR) in normal children to aged volunteers using Tc-99m HMPAO. MATERIALS AND METHODS: Thirty four right-handed normal volunteers (20 males, 14 females, mean age 40.3+/-24.9 years, range 4 to 82 years) were underwent rest/acetazolamide (ACZ) brain SPECT using Tc-99m HMPAO and the sequential injection and subtraction method. rCBF was estimated on the basis of a semiquantitative approach by means of right/left ratio, region/cerebellum and region to whole brain ratios in frontal, parietal, temporal, and occipital lobes, basal ganglia, thalami, and cerebellum. CVR was measured by means of % perfusion increase calculated as % mean count change compared to rest rCBF in each regions. RESULTS: Mean values of right to left ratios range from 1.004 to 1.018. rCBF was highest in cerebellum and lowest in basal ganglia and thalami. Frontal and temporal rCBF decreased while occipital and thalamic rCBF increased according to age. No sexual difference of rCBF was noted. Mean CVR was 29.9+/-12.9%. Mean CVR significantly increased to late teens, and declined thereafter. After 6th decade, CVR in both frontal lobes, left parietal lobe and right basal ganglia decreased significantly with advancing age. There was no sexual difference of CVR. CONCLUSION:: Quantitative assessment of CVR was possible by ACZ Tc-99m HMPAO brain SPECT. It revealed that rCBF and CVR changed according to age in normal Korean volunteers. There was no sexual difference.

Comparison of Diagnostic Performance between Interictal F-18-FDG PET and Ictal Tc-99m-HMPAO SPECT in Occipital Lobe Epilepsy / 대한핵의학회잡지

PURPOSE: Interictal F-18-fluorodeoxyglucose (FDG) PET and ictal Tc-99m-HMPAO SPECT are found to be useful in localizing epileptogenic zones in neocortical lateral temporal or frontal lobe epilepsy. We investigated whether interictal F-18-FDG PET or ictal Tc-99m-HMPAO SPECT was useful to find epileptogenic zones in occipital lobe epilepsy (OLE). MATERIALS AND METHODS: We reviewed patterns of hypometabolism in interictal F-18-FDG PET and of hyperperfusion in ictal Tc-99m-HMPAO SPECT in 17 OLE patients (mean age=27+/-6.8 year, M:F=10:7, injection time=30+/-17 sec). OLE was diagnosed based on invasive electroencephalography (EEG) study, surgery and post-surgical outcome (Engel class I in all for average 14 months). RESULTS: Epileptogenic zones were correctly localized in 9 (60%) out of 15 patients by interictal F-18-FDG PET. Epiletogenic hemispheres were correctly lateralized in 14 patients (93%). By ictal Tc-99m-HMPAO SPECT, epileptogenic hemispheres were correctly lateralized in 13 patients (76%), but localization was possible only in 3 patients (18%). Among patients who showed no abnormality with MR imaging and no correct localization with ictal Tc-99m-HMPAO SPECT, interictal F-18-FDG PET was helpful in 2 patients. CONCLUSION:: Ictal Tc-99m-HMPAO SPECT was helpful in lateralization but not in localization in OLE. Interictal F-18-FDG PET was helpful for localization of epileptogenic zones even in patients with ambiguous MR or ictal SPECT findings. Key KW: Occipital lobe epilepsy, Tc-99m-HMPAO, Ictal perfusion SPECT, F-18-FDG, PET, SPECT