ReVersible Changes of Clinical Chemical Tests in Severe Hypothyroid Patients with Differentiated Thyroid Cancer Who Were Admitted for Radioiodine Therapy

PURPOSE: Severe hypothyroidism can cause abnormalities in numerous clinical chemical test results. We observed various reVersible changes of clinical chemical test results in patients with severe hypothyroidism who were admitted for radioiodine ablation therapy after total thyroidectomy. The purpose of this study was to describe and discuss the findings. METHODS: The study comprised 168 patients (24 males, 144 females, mean age 49+/-14 years) who underwent total thyroidectomy due to differentiated thyroid cancer and who were admitted for I-131 ablation therapy. Patients who had hepatic or renal dysfunction were excluded. RESULTS: Serum mean levels of aspartate transaminase, alanine transaminase, cholesterol, high density lipoprotein, lactic dehydrogenase, total bilirubin, indirect bilirubin, and creatinine were significantly increased to the upper normal range during severe hypothyroid state (serum thyroid stimulating hormone >30 uIU/ml). While serum levels of alkaline phosphatase (ALP), triglyceride (TG) and blood urea nitrogen (BUN) remained unchanged. Six patients who showed abnormal serum creatinine level during hypothyroid condition returned to normal after recovery of thyroid function. CONCLUSION: Results of clinical chemical tests for hepatic, lipid and renal function are often increased reversibly in severely hypothyroid patients. Reversible, abnormal serum creatinine levels may develop in some cases. Follow-up study is necessary in induced severely hypothyroid patients for radioiodine therapy to differentiate the reversibility of chemical tests.

A New Porcine Model of Ischemic Heart Failure and Pathologic Findings by Intra-Coronary Injection of Ethanol

BACKGROUND AND OBJECTIVE: A new porcine model of acute myocardial infarction (AMI), ischemic heart failure and pathologic findings of coronary artery by a transcatheter intracoronary ethyl alcohol injection has been developed. MATERIALS AND METHODS: Twelve female pigs underwent a transcatheter injection in the left anterior descending artery (LAD), using alcohol, to produce an apicoanteriorseptal AMI. Low pressure ballooning using a 2.5 mm over-the-wire balloon, just above the second and first diagonal branches, followed by a 1 mL injection of 99.9% ethyl alcohol was administered to 8 and 4 pigs, respectively. Follow-up coronary and left ventricular (LV) angiograms and echocardiography were performed 4 weeks after the alcohol injection. Myocardial SPECT using 201Tl (and 99mTc-MIBI) and triphenyl tetrazolium chloride (TTC) stain were performed after sacrifice. The quantity of TTC stain and amount of 201Thallium uptake were compared using the Vision Workstation. The histopathological findings of the infarcted myocardium and coronary artery were demonstrated after 28 days. RESULTS: Procedure-related mortality was observed in two-pigs of the proximal LAD injection group. Four pigs suffered from ventricular tachycardia, which was converted into sinus rhythm by dc cardioversion. The four-week follow-up coronary angiography revealed persistently occluded LAD in all pigs. The LV angiogram showed akinetic movement in the apicoanteriorseptal wall with an ejection fraction of 46.5+/-3.3%. Myocardial SPECT revealed a perfusion defect in the apicoanterior wall of all pigs. The percentage area of perfusion defect was 22.2+/-3.06%. The TTC did not stain the myocardium in the apicoanterior wall. The percentage of non-stained myocardium was 23.5+/-2.70%. A histological examination revealed severe fibrosis in the infarcted myocardium and massive thrombus, with organization and calcification. CONCLUSION: The porcine model of acute myocardial infarction using an intracoronary ethanol injection into the distal LAD is safe, reliable and reproducible, and can be used for future research into myocardial regeneration and ischemic LV failure.

The Effects of Radiation Using Ho-166 on Endothelial Function in a Porcine Coronary Model

BACKGROUND AND OBJECTIVES: It has been reported that intracoronary radiation therapy (ICRT) using a Ho-166 coated balloon inhibits restenosis of porcine coronary arteries. However, the consequences of ICRT on coronary artery endothelial function are unknown. The aim of this study is to investigate the effects of ICRT using a Ho-166 balloon on coronary artery endothelial function and vasomotor reactivity. MATERIALS AND METHODS: Female pigs (25-35 kg) were orally premedicated daily with aspirin (100 mg) and ticlopidine (250 mg) for the duration of the study. Under sterile conditions with local anesthesia of the skin provided by 2% lidocaine, an arteriotomy of the left carotid artery was performed, an 8 Fr sheath was inserted, and intraarterial heparin sodium (10,000 IU) was injected. Under fluoroscopic guidance, the coronary artery main branch was selected through an 8 Fr guiding catheter for coronary artery overdilation injury (balloon to artery ratio, 1.3:1) and ICRT. A Ho-166 coated balloon prepared to deliver 20 Gy at a depth of 2 mm from the balloon surface was used for ICRT. The coronary artery main branch in each pig was randomly assigned to either balloon injury (Group I) or balloon injury plus ICRT (Group II). Coronary artery segments were taken from the animals at 0 week (n=8), 4 weeks (n=6) and 8 weeks (n=8) after the intervention. Data in each group denote the relative ratio compared to non-injured coronary artery and are expressed as mean +/- standard error of mean. RESULTS: The degree of KCl-induced contractile response (g) was not different between the two groups at 0 and 4 weeks, but was significantly decreased in group II compared to group I at 8 weeks (I:1.04+/-0.06, II:0.79+/-0.07, p=0.014). In rings precontracted with prostaglandin F 2alpha (PGF 2alpha), the degree of NO-dependent relaxation (%) induced with substance P was significantly decreased in group II compared to group I at 0 week (I:0.93+/-0.33, II:0.47+/-0.31, p=0.03), but the difference between the two groups was not significant at 4 and 8 weeks. In rings precontracted with PGF 2alpha and LAME in the presence of indomethacin, the degree of EDHF-induced relaxation (%) using substance P was not different between the two groups at 0, 4 and 8 weeks; nor was the degree of sodium nitroprusside-induced endothelium independent relaxation (%) in depolarized conditions with PGF 2alpha. CONCLUSION: Endothelial function of the porcine coronary artery is only transiently impaired after ICRT using a Ho-166 coated balloon. Therefore this therapy can be used as an effective method to prevent restenosis after percutaneous coronary intervention.

Diffusion Weighted MRI and Tc99m-ECD SPECT inAcute Middle Cerebral Artery Territory Infarction: Comparison with Clinical Status and Outcome Using Volumetric Analysis"

BACKGROUND: Diffusion weighted magnetic resonance imaging (DWI) and single photon emission computed tomography (SPECT) can demonstrate ischemic brain injury within the first several hours after the onset of symptoms. We investigated the utility of combined DWI and SPECT in the assessment of acute cerebral infarction. METHODS: Nineteen patients with acute middle cerebral artery territory infarction underwent DWI and SPECT within 12 hours of symptom onset (mean, 9.6 hour). In SPECT, we defined abnormality as a perfusion defect region (perfusion ??30% compared to a normal cortex) and an ischemic region (perfusion difference ??10% compared to a contralateral normal hemisphere). The initial DWI and SPECT lesion volume ratios (lesion volume / hemispheric volume) were analyzed with subsequent neurological deficits as determined by the National Institutes of Health Stroke Scale (NIHSS) score and Barthel index (BI). RESULTS: There was a high correlation between clinical scores within 7 days and lesion volumes determined by DWI and SPECT respectively (p<0.05). The lesion volumes detected by DWI and SPECT significantly correlated with each other (p<0.01). Ischemic lesions on SPECT were larger in the group (n=10) with ICA occlusions than in the other group (p=0.034). In 15 patients with cortical lesions, the ratio of perfusion defect volumes on SPECT to lesion volumes on DWI was higher in the group with favorable outcome than in the group with unfavorable outcome (p=0.01). CONCLUSIONS: Both DWI and SPECT are highly correlated with the severity of neurological deficit in acute cerebral infarction. Furthermore, combined use of DWI and SPECT would be more powerful than either study alone in predicting clinical outcome. (J Korean Neurol Assoc 19(2):88~95, 2001)

Diffusion Weighted MRI and Tc99m-ECD SPECT inAcute Middle Cerebral Artery Territory Infarction: Comparison with Clinical Status and Outcome Using Volumetric Analysis"

BACKGROUND: Diffusion weighted magnetic resonance imaging (DWI) and single photon emission computed tomography (SPECT) can demonstrate ischemic brain injury within the first several hours after the onset of symptoms. We investigated the utility of combined DWI and SPECT in the assessment of acute cerebral infarction. METHODS: Nineteen patients with acute middle cerebral artery territory infarction underwent DWI and SPECT within 12 hours of symptom onset (mean, 9.6 hour). In SPECT, we defined abnormality as a perfusion defect region (perfusion ??30% compared to a normal cortex) and an ischemic region (perfusion difference ??10% compared to a contralateral normal hemisphere). The initial DWI and SPECT lesion volume ratios (lesion volume / hemispheric volume) were analyzed with subsequent neurological deficits as determined by the National Institutes of Health Stroke Scale (NIHSS) score and Barthel index (BI). RESULTS: There was a high correlation between clinical scores within 7 days and lesion volumes determined by DWI and SPECT respectively (p<0.05). The lesion volumes detected by DWI and SPECT significantly correlated with each other (p<0.01). Ischemic lesions on SPECT were larger in the group (n=10) with ICA occlusions than in the other group (p=0.034). In 15 patients with cortical lesions, the ratio of perfusion defect volumes on SPECT to lesion volumes on DWI was higher in the group with favorable outcome than in the group with unfavorable outcome (p=0.01). CONCLUSIONS: Both DWI and SPECT are highly correlated with the severity of neurological deficit in acute cerebral infarction. Furthermore, combined use of DWI and SPECT would be more powerful than either study alone in predicting clinical outcome. (J Korean Neurol Assoc 19(2):88~95, 2001)

Contralateral Hyperperfusion on Single Photon Emission ComputedTomograhy (SPECT) in the Patient with Todd's Paralysis

It has been known that the usual findings of SPECT in patients with Todd's paralysis is the hypoperfusion of the corresponding hemisphere. We experienced a patient who developed transient hemiparesis after a seizure attack with hyperperfusion rather than hypoperfusion over the corresponding hemisphere on brain SPECT. A 36-year-old female presented with left hemiparesis after a secondarily generalized tonic seizure. No additional seizure-like attack was noted during admission. EEG showed intermittent focal slow waves over the right frontotemporal area on admission and returned to a normal pattern 72 hours after admission. Tc-99m ECD SPECT showed hyperperfusion on the right frontoparietal area in spite of the normalization of EEG. The degree of hyperperfusion was diminished as time passed for at least 72 hours. We report a patient who had Todd's paralysis associated with contralateral frontoparietal hyperperfusion. Todd's paralysis may be explained as the result of focal discharges that lead to local vasomotor changes.

Sialolithiasis Mimicking Metastatic Thyroid Cancer / 대한핵의학회잡지

We report a false positive case of I-131 scan due to a sialolithiasis in right submandibular gland. I-131 images showed not only remnant thyroid tissues and functional metastases in the anterior neck but also a hot uptake near right submandibular gland. We confirmed the sialolithiasis by radiologic studies. Sialolithiasis should be regarded as a false positive cause when I-131 scan shows a hot spot near salivary bed.

Asymmetry of Medial and Lateral Tempora) Regional Glucose Metabolism in Temporal Lobe Epilepsy by F-18-FDG PET / 대한핵의학회잡지

PURPOSE: We investigated the difference of glucose metabolism of medial and lateral temporal lobes of patients with temporal lobe epilepsy (TLE) utilizing quantitative comparison of regional metabolic activities using asymmetric index. MATERIALS AND METHODS: We studied 19 pathologically proven mesial TLE and 25 lateral TLE patients. Lateral TLE patients were either normal on magnetic resonance imaging (cryptogenic: n=14) or had structural lesions (lesional: n=11). Asymmetric index (ASI) was calculated as [(ipsilateral-contralateral)/(ipsilateral+ contralateral)]x200. RESULTS: ASI of medial and lateral lobes of mesial TLE was decreased (-16.4+/-8.3 and -12.7+/-5.5, respectively). In cryptogenic lateral TLE, ASI of lateral temporal lobe was decreased (-11.8+/-4.7), whereas that of medial temporal lobe was not decreased (-4.6+/-6.3). ASI of medial lobe of lesional lateral TLE was -7.3+/-9.1, which was significantly different from that of mesial TLE (p<0.05). Patients with lesional lateral TLE had evident metabolic defects or decrease (ASI: -22+/-10.5) in lateral temporal lobe. While we could not find the difference of metabolic activity in lateral temporal lobes between cryptogenic lateral TLE and mesial TLE patients, the difference of metabolic activity was significant in medial temporal lobes which was revealed by ASI quantitation. CONCLUSION: Asymmetric decrease of metabolic activity in both medial and lateral temporal lobes indicates medial temporal epilepsy. Symmetry of metabolic activity in medial temporal lobe combined with asymmetry of that in lateral temporal lobe may give hints that the epileptogenic zone is lateral.

A Comparison Study of Metaphase Analysis of Chromosomal Aberration and Flow Cytometric Assessment of Radiation- induced Apoptosis in Human Peripheral Lymphocytes / 대한핵의학회잡지

PURPOSE: Radiation-induced chromosomal damage and apoptosis were compared in human lymphocytes. MATERIALS AND METHODS: Peripheral lymphocytes from 10 normal volunteers (6 males, 4 females, age range 23~41 years) were irradiated by gamma rays from a cell irradiator. Doses of irradiation were 0 (control), 0.18, 2, 5, 10, 20 and 25 Gy. Irradiated lymphocytes were examined by metaphase analysis for chromosomal aberrations and by flow cytometry for apoptosis. RESULTS of both studies were compared according to dose. RESULTS: Number of dicentric and ring chromosomes (D+R) was 0.5+/-0.53 at baseline, which was significantly increased after radiation according to the dose. The fraction of cells showing annexin V-fluore-scein isothiocyanate uptake was 0.55+/-0.39%, which increased to 3.58+/-1.85% by 2 Gy irradiation, and then decreased. The fraction of cells showing propidium iodide (PI) uptake was 0.52+/-0.12%, which significantly increased according to dose (upto 15.64+/-5.99% by 20 Gy irradiation). D+R and PI uptake were well correlated (r=0.84, p<0.001). CONCLUSION: Radiation-induced chromosomal aberration was correlated to nuclear uptake of PI, a marker of late apoptosis.

Role of Dacryoscintigraphy in the Diagnosis and Treatment of Pediatric with Epiphora / 대한핵의학회잡지

PURPOSE: We conducted this study to evaluate the role of dacryoscintigraphy in the diagnosis and treatment of pediatric patients with epiphora. MATERIALS AND METHODS: In 58 patients aged from 2 months to 15 years (mean age 2.8+/-2.3 years), dacryoscintigraphy was performed using a gamma camera with 4 mm pinhole collimator. We correlated symptoms with dacryosicntigraphic findings in all patients. In 37 patients who underwent ophthalmologic procedures, we analyzed the agreements of dacryoscintigraphic findings with the operation. RESULTS: High rates of agreements between epiphora and obstruction on dacryoscintigraphy (69/72, 95.8%), and between scintigraphic obstructive findings and operation sites (44/47, 93.6%) were noted. Nine of fourty-four (20.5%) asymptomatic eyes showed obstructive findings on dacroscintigraphy. CONCLUSION: In pediatric patients with epiphora, dacryoscintigraphy is a useful tool not only in diagnosing nasolacrimal duct obstruction but also in making a decision for therapeutic procedures.

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.

Cytogenetic Radiation Adaptive Response Assessed by Metaphase Analysis and Micronuclei Test in Human Lymphocytes and Mouse Bone Marrow Cells / 대한핵의학회잡지

PURPOSE: Radiation adaptive response in human peripheral lymphocytes and mouse bone marrow cells was investigated using both metaphase analysis and micronucleus assay. We assessed the correlation between both tests. MATERIALS AND METHODS: Two groups of the human peripheral lymphocytes and mouse bone marrow cells were exposed to low dose (conditioning dose, 0.18 Gy) or high dose (challenging dose, 2 Gy) gamma-rays. The other 4 groups were exposed to low dose followed by high dose after several time intervals (4, 7, 12, and 24 hours, respectively). The frequencies of chromosomal aberrations in metphase analysis and micronuclei in micronucleus assay were counted. RESULTS: Chromosomal aberrations and micronuclei of preexposed group were lower than those of the group only exposed to high dose radiation. Maximal reduction in frequencies of chromosomal aberrations were observed in the group to which challenging dose was given at 7 hour after a conditioning dose (p<0.001). Metaphase analysis and micronucleus assay revealed very good correlation in both human lymphocytes and mouse bone marrow cells (r=0.98, p<0.001; r=0.99, p=0.001, respectively). CONCLUSION: Radiation adaptive response could be induced by low dose irradiation in both human lymphocytes and mouse bone marrow cells. There was a significant correlation between metaphase analysis and micronucleus assay

Gender Difference of Accuracy in Detecting Coronary Artery Disease by Myocardial Perfusion SPECT / 대한핵의학회잡지

PURPOSE: Myocardial SPECT is an effective test for detecting coronary artery disease in the general population. But the diagnostic accuracy between sexes is not defined. The purpose of this study is to compare the diagnostic accuracy between males and females. MATERIALS AND METHODS: One hundred and seventy seven male and 98 female patients who underwent myocardial SPECT within 1 month of coronary angiography were studied. Myocardial SPECTs were considered abnormal if fixed or reversible perfusion defects were detected. Stenosis severity of > or = 50% luminal diameter reduction of any artery defined coronary artery disease (CAD). RESULTS: Overall sensitivity for detection of CAD was 98% in men and 97% in women (p=not significant). However, specificities, accuracies, and positive predictive values (PPV) in men and women were 49% vs 31% (p<0.05), 81% vs 57% (p<0.01), 78% vs 48% (P<0.01), respectively Diagnostic accuracies for detection of right coronary artery disease were not different in both sexes, however, accuracies for detection of left anterior descending artery disease and left circumflex artery disease were significantly lower in female (p<0.05). CONCLUSION: A significant difference of diagnostic accuracy between sexes, especially in LAD and LCx disease, was noted. Artifacts from breast attenuation might be a cause for the lower diagnostic accuracy in female.

Comparison of 99mTc-tetrofosmin and 99mTc-sestamibi Myocardial Perfusion SPECT in Detecting Coronary Artery Fisease / 대한핵의학회잡지

PURPOSE: Tc-99m-tetrofosmin(TF) is a recently proposed myocardial imaging agent which has similar biokinetic characteristics to Tc-99m-sestamibi(MIBI). The aim of this study was to compare TF and MIBI myocardial perfusion SPECTs in detecting coronary artery disease. MATERIALS AND METHODS: One hundred and sixty patients(l0l males, 59 females, mean age 57+/-9 yr) who had undergone both myocardial perfusion SPECT (M- SPECT) and coronary angiography within 1 month were studied. M-SPECT was performed using TF in 115 patients and MIBI in 45 patients. Stress-rest one day protocol was used in all patients A coronary stenosis was considered significant when the luminal diameter > or =50% was compromised. The chi square test was used to compare, differences in sensitivity and specificity between the two groups. RESULTS: There was no difference in age and diseased coronary artery branches between the two groups. There were more male patients in TF group: Male-to-female ratios of TF and MIBI groups were 78:37 and 23:22, respectively (p<0.05). The overall sensitivity of TF study was 92% and specificity 36%. The overall, sensitivity and specificity of MIBI study were 93% and 30% respectively. There was no difference between TF and MIBI groups in identifying individual diseased coronary artery branches. CONCLUSION: One day stress-rest myocardial SPECT using either TF or MIBI was comparable and was a very sensitive test in detecting coronary artery disease.

Tc-99m Myocardial Perfusion SPECT Findings of Angina Patients Showing Normal Coronary Angiography

BACKGROUND: Tc-99m myocardial perfusion imaging agents have recently found wide spread use as detecting agents of coronary diseases. Unfortunately, false positive results are not infrequent. METHODS: We analyzed Tc-99m myocardial perfusion SPECT (Tc-SPECT) findings in angina patients showing normal coronary angiography. Seventy patients who underwent myocardial SPECT wihin one month of coronary angiography which revealed no significant stenosis were studied. RESULTS: Forty six (65.7%) patients showed perfusion defects on Tc-SPECT. Eighteen were due to soft tissue attenuation, thirteen were due to technical problems such as low count rate, six were associated with intraventricular conduction abnormalities, four with coronary spasms, three with old infarctions, and one with slow coronary flow. CONCLUSION: Photon attenuation and inadequate count rates were the main causes of false positive results on myocardial SPECT imaging with Tc-99m agents. However, pathological conditions such as conduction disturbance, coronary spasm or slow coronary flow were also associated with positive SPECT findings in patients with normal coronary angiograms.

Comparison of Stress-rest and Rest-stress One Day Myocardial Perfusion Scintigraphies in Detecting Coronary Artery Diseases / 대한핵의학회잡지

It has been shown that both rest and stress myocardial perfusion imagings with technetium agents can be performed on the same day using two different doses injected within few hours. The purpose of this study was to compare the two protocols (stress-rest and rest-stress) in detecting coronary artery diseases. One hundred and sixty patients (101 males, 59 females, mean age 57+/-9 years) and 120 patients (79 males, 41 females, mean age 59+/-10 years) underwent stress-rest myocardial perfusion SPECT and rest-stress myocardial perfusion SPECT, respectively All of them underwent both myocardial perfusion SPECT and coronary angiography within 1 month. A coronary stenosis was considered significant when it compromised the luminal diameter by> or =50%. The chi square test was used to compare differences in sensitivity, specificity and accuracy between the two groups. The overall sensitivity, specificity and accuracy of stress-rest protocol were 99%, 35%and 68%, respectively. Those of rest-stress protocol were 96%, 47%, and 78%, respectively. There was no difference between the two protocols in identifying individual diseased coronary artery branches. Therefore, one day stress-rest and rest-stress myocardial SPECT using Tc-99m agents were comparable and were very sensitive tests in detecting coronary artery diseases.

Predictive Values of Gated Myocardial SPECT for Wall Motion Improvement After Bypass Surgery / 대한핵의학회잡지

We studied to investigate the predictive values of gated SPECT for the improvement of wall motion after bypass surgery. As we compared postoperative SPECT with preoperative ones, we defined viability as wall motion improvement. We performed rest 71-201/stress Tc-99m-MIBI gated SPECT in 25 patients before and 3 months after bypass surgery. Myocardial wall motion was graded as normal, hypokinesia, akinesia, and dyskinesia by pair-wise visual analysis of gated pre and postoperative SPECT's on the same monitor screen. Myocardial wall thickening was determined good or poor Among 92 segments with wall motion abnormalities before operation, 69 (75%) improved and 23 did not. Before operation, we could find segments with good systolic thickening in 64 segments among total 92. Thickening of the remaining 28 was poor. Wall motion improved postoperatively in 45 segments (70%) among 64 with good thickening. Twenty four(86%) among 28 segments with poor thickening had also improved. We grouped segments into mild(hypokinetic) and severe(akinetic/dyskinetic) ones. Among 33 segments with severe motion abnormalities, 14 had good thickening and 19 did not. Nine(60%) improved out of 14 segments having severe abnormality with good thickening. However, 16(84%) segments out of 19 having severe abnormality with poor thickening also improved. Neither degree of perfusion decrease nor severity of wall motion abnormalities could explain the high rate of false negatives. In conclusion, as we defined viability as wall motion improvement by comparing pre and postoperative SPECT, systolic thickening observed by gated Tc-99m-MIBI SPECT in myocardial segments with wall motion abnormalities predicted wall motion improvement after bypass surgery. However, poor thickening could not be referred as evidence of nonviable myocardium both in mild and severe contractile dysfunction, so that we might need stimulation study such as dobutamine echocardiography or dobutamine gated SPECT.

Prognostic Implication of Normal Myocardial Perfusion Scintigraphy in Patients with Chest Pain / 대한핵의학회잡지

Myocardial scintigraphy is a widely used noninvasive procedure with high sensitivity for the detection of patients with suspected coronary artery disease. The purpose of this study was to determine the prognostic value of a normal myocardial scintigraphy in 292 patients (150 males, 142 females, mean age 53+/-12 years) with chest pain who were followed from 7 to 58 (mean 25) months. Myocardial SPECT was performed with Tc-99m MIBI in 173 patients, with Tc-99m tetrofosmin in 74 patients and with T1-201 in 45 patients. During the follow-up period, there were 2 cardiac deaths and 2 nonfatal myocardial infarctions resulting in cardiac event rate of 1.37% (0.66% per year). The cardiac event rate was not different in patients with angiographically normal coronary arteries (1/30, 3.3%) and in those who had significant coronary a disease (2/27, 7.4%) (p=0.60). In conclusion, patients with chest pain and normal myocardial scintigraphy have a low cardiac event rate, and there was no significant difference of cardiac event rates between patients with normal and abnormal coronary angiograms.

Alterations in Thyroid Hormone Levels after Open Heart Surgery / 대한흉부외과학회지

The hemodynamic effects of thyroid hormones which is well established, affect myocardial contractility, heart rate, and myocardial oxygen consumption. The alterations in thyroid function test are frequently seen in patients with nonthyroidal illness and often correlate with the severity of the illness and the prognosis. In this study, thyroid hormone changes were investigated in 20 patients who received cardiopulmonary bypass(CPB). All patients showed a state of biochemical euthyroidism preoperatively. The results were as follows : 1. Serum triiodothyronine(T3) reached to its nadir(30.05+/-17.5ng/dl, p<0.001) at 10 minutes after the start of CPB and remained low(p<0.05) throughout the study period. 2. Serum thyroxine(T4) concentration slightly decreased after CPB, but maintained within normal range. 3. Serum free thyroxine(fT4) concentration slightly increased after CPB, but maintained within normal range. 4. Serum thyroid stimulating hormone(TSH) concentration increased 10 minute after CPB, reached to its nadir(3.37+/-0.81uIU/ml, p<0.001) at 2 hours after CPB. After then, serum TSH concentration decreased and reached its normal levels at 24 hours after CPB. 5. The patients whose postoperative recovery was uneventful(Group 1) had higher serum T3 levels than those who had postoperative complications(Group 2)(p<0.05). Group 1 showed elevating patterns of serum T3 in the fourth day after operation, whereas group 2 did not show such an elevating pattern. These findings are similar to the euthyroid sick syndrome seen in severely ill patients and indicate that patients undergoing open heart surgery have suppression of the pituitary-thyroid axis.

Neuronal migration disorders: MRI, SPECT and PET findings

BACKGROUND: With the aid of high-resolution MRI, the identification of neuronal migration disorder(NMDs) is increasing and NMDs are considered as one of the major causes of extrahippocampal epilepsy. However, MRI has some limitatons in detecting small cortical lesion of NMDs. We have studied the diagnostic value and findings of brain SPECT and PET in the patients with NMDs. METHODS: Nineteen NMD patient with intrac table and partial epilepsy were studied. Diagnosis of NMDs was based on neuroimaging and pathology. Proton, Tl and T2-weighted axial, saggital and coronal MR image were obtained by 1.5 Tesla unit. Interictal and ictal SPFCT and PET imagings were performed with 99mTc-HMPAO and 18F-fluorodeoxyglucose. RESULT: Focal cortical dysplasia (FCD) and schizencephaly were detected in 4 patients, heterotopias in 3(one with 3 isolated lesions and one with bilateral temporal lobe lesions), polymicrogyria in 3, hemi-megalencephaly in 2, pachygyria in 2, forme fruste of tuberculous sclerosis(FFTS) in 1. Heterotopia was also combined with other lesions as schizencephaly, FFS and pachygyria. The MRI detected the lesions in 14 patients(73.7%). Of the 5 patients without definite abnormalities on MRI, 3 had focal polymicrogyda and 2 had FCD on pathologic examination. The interictal SPECT revealed abnormalities in 9 of 12 patients(75.0%), but could not detect 2 FCDs and one heterotopia. The ictal SPECT detected the lesions in all 11 patients. PET showed the compatible abnormalities in 17 patients(89.5%), but there was no abnormal finding in 2(1 with FCD and 1 with heterotopia). The abnormal lesions in PET were more extensive than those in MRI in the 8 patients with focal NMDs. Heterotopia showed cortical gray matter activity on PET in 6 out of 11 lesions. All other NMDs showed hypometabolism or metabolic detect in the interictal SPECT and PET. CONCLUSION: Functional imaging as SPECT & PET may be more selective than MRI to detect focal cortical lesions in NMD. NMDs show, variable metabolic pattern on functional imagings and in general the derangement in the functional imaging is more widespread than the lesions detected by MRI. We recommend the functional neuroimaging in the patients who are suspected to have partial seizure of neocortical origin and have no abnormal findings on brain MRI.