Satisfaction of the "Mister Employee": a goal to be reached]

Six patients with pulmonary emphysema scheduled to undergo thoracoscopic lung volume reduction surgery (TLVRS) were evaluated by three-dimensional (3-D) dynamic pulmonary xenon-133 SPECT. Serial 30-second dynamic SPECT data for equilibrium and washout (for 5 min) were acquired using a continuous repetitive rotating acquisition mode with a triple-detector SPECT system. SPECT data were reconstructed to 3-D images with a color, surface-rendering technique, and a 3-D fusion image of the 3-min washout image over the equilibrium image was obtained. Regional ventilation was visually assessed on the fusion 3-D images and quantified by xenon-133 half-washout time (T1/2) and mean transit time (MTT). The 3-D fusion image localized and lateralized the worst diseased sites with xenon-133 retention. Xenon-133 retention, T1/2 and MTT were reduced on these images in five patients with improved pulmonary function tests following TLVRS. However, xenon-133 retention was greater in one with asynchronous diaphragm movement after TLVRS. This modality will assist TLVRS in determining the lung resection target and in evaluating the treatment effect.     

Fast acquisition of myocardial SPECT images with Tc-99m sestamibi for the diagnosis of coronary artery disease

BACKGROUND: Shortening the acquisition time for myocardial single-photon emission computed tomographic (SPECT) imaging increases patient comfort and laboratory throughput. The purpose of this study was to compare the diagnostic accuracy for coronary artery disease detection of myocardial SPECT images acquired in 5 to 10 minutes versus 25 minutes using Tc-99m methoxyisobutylisonitrile (Tc-99m sestamibi) and a single-head gamma camera. METHODS AND RESULTS: Forty-one subjects had a standard 1-day rest/stress Tc-99m sestamibi myocardial SPECT study. Two sets of rest and stress images were acquired on the same day for each subject. One set of images was acquired with a 5- to 10-minute fast acquisition protocol; the second set of images was acquired with a 25-minute standard protocol. The accuracies of the fast and standard protocols for identifying individuals with and without coronary artery disease were equivalent. Accuracy was 76% for the fast protocol and 73% for the standard protocol in individuals with at least one coronary stenosis > or = 70%. The accuracies of the two protocols for identifying individual coronary arteries with stenoses > or = 70% also were equivalent. Accuracy was 77% for the fast protocol and 74% for the standard protocol. CONCLUSIONS: SPECT myocardial images may be acquired in as little as 5 to 10 minutes using Tc-99m sestamibi and a 1-day rest/stress protocol. Accuracy is equivalent to that attained in studies with longer imaging times.     

Arteriovenous fistula after renal biopsy in children

Tc-99m MIBI is used as a tumor imaging agent and has been proposed to measure p-glycoprotein function, which plays an important role in tumor multidrug resistance to chemotherapy. It has been reported that lung cancer and breast cancer with a high retention of Tc-99m MIBI have been more responsive to chemotherapy than tumors with low retention. Thus Tc-99m MIBI SPECT could be used as a measure of p glycoprotein function and consequently may serve as a predictor of the tumor's responsiveness to chemotherapeutic agents. Described here are two patients with lymphomas, one with non-Hodgkin's lymphoma and the other with Hodgkin's disease, who underwent Tc-99m MIBI thoracic SPECT before and after chemotherapy. The sequential studies demonstrated a reduction in tumor size and diminished tumor uptake in one patient and disappearance of tumor uptake after a course of chemotherapy in the other patient. The data suggest that elevated Tc-99m MIBI uptake in a tumor as a result of retention by p glycoprotein not only demonstrates mediastinal involvement of lymphomas but also may be used to forecast responsiveness to chemotherapy.     

Effect of vitamin A on small intestinal brush border enzymes in a rat

To determine the utility of the myocardial tracer Tc-99m-tetrofosmin in the examination of patients with left bundle branch block (LBBB) and to investigate Tc-99m-tetrofosmin uptake and retention in the myocardium, early and delayed Tc-99m-tetrofosmin SPECT was performed in 10 patients having LBBB without coronary stenosis. METHODS: After 740 MBq of Tc-99m-tetrofosmin injection in the resting state, the early and delayed SPECT imaging was done at 30 min and 180 min, respectively. RESULTS: Decreased Tc-99m-tetrofosmin uptake in the septal segments was observed in 4 patients (40%) at 30 min and in 9 (90%) at 180 min. Reverse redistribution was seen in 9 of 10 patients. In patients with LBBB, the septal-to-lateral uptake ratio was lower in the delayed images than in the early images (0.80 +/- 0.09 vs. 0.89 +/- 0.09, p < 0.001). In patients with LBBB, the washout rate of Tc-99m-tetrofosmin was higher in the septal segments than in the lateral segments (28.3 +/- 4.3% vs. 22.8 +/- 3.3%, p < 0.001). CONCLUSION: The SPECT data indicate that in LBBB without coronary stenosis, the uptake of Tc-99m-tetrofosmin is decreased in the septal wall, and that reverse redistribution occurs frequently. Our results contribute to the elucidation of both the cellular biokinetics of Tc-99m-tetrofosmin in the myocardium and the hemodynamics of the septum in LBBB, and indicate the possible clinical utility of Tc-99m-tetrofosmin.     

Immunologic diagnosis of central nervous system viral infection

We studied the hepatic functional reserve in the lobes of the liver in 28 patients with chronic liver disease and 13 controls using single photon emission computed tomography (SPECT) imaging with a radiolabeled asialoglycoprotein analog, Technetium-99m-diethylenetriaminepentaacetic acid-galactosyl-human serum albumin (Tc-99m GSA). Counts of Tc-99m GSA radioactivity in the liver on SPECT images significantly correlated (P < .0001) with the serum albumin level (r = .612), log (serum cholinesterase activity) (r = .618), serum bilirubin level (r = .628), prothrombin time (r = .715), hepaplastin test (r = .637), and indocyanine green retention rate at 15 minutes (r = .771), making it possible to estimate the distribution of functional reserve in the liver based on counts. Using the intact hepatocyte theory, we estimated the number of viable hepatocytes based on the counts. With progression of hepatic functional degeneration, counts per unit hepatic volume decreased (rho = .779, P < .0001), and left lobe to right lobe ratio of this parameter increased (rho = .491, P = .0019) significantly. These findings suggest that the reduction of hepatic functional reserve per unit hepatic volume and numerical density of the hepatocytes, and the proliferation of fibrosis in patients with chronic liver disease is slower in the left lobe than in the right. We discuss a possible biological basis for these apparent lobar differences and for hepatic morphological changes seen in cirrhosis.     

Surface expression and release of soluble forms of CD8 and CD23 in CD40- and IL-4-activated mononuclear cells from patients with Graves'' disease (GD)

OBJECTIVE: This study was performed to assess the usefulness of preoperative thin-section CT alone and in combination with physiologic measurements in emphysema patients being evaluated for lung volume reduction surgery. SUBJECTS AND METHODS: Six 1-mm collimation sections through the chest were obtained in 20 patients being evaluated for lung volume reduction surgery. Extent and severity of emphysema were assessed by visually scoring the images. CT scores ranged from 0 to 144. Inspiratory resistance was measured in 12 of 20 patients and was also used to discriminate between responders (change in forced expiratory volume in 1 sec, > or = 150 ml after surgery) and nonresponders (change in forced expiratory volume in 1 sec, < 150 ml after surgery). RESULTS: Four of 20 patients with mild emphysema as revealed by thin-section CT (scores of < 50) did not improve lung function after lung volume reduction surgery. Eight of the remaining 16 patients with moderate to severe emphysema as revealed by thin-section CT (scores of > 50) underwent inspiratory resistance measurement. Those seven patients whose inspiratory resistance measurement exceeded 8.5 cm H2O/l per second did not respond favorably to lung volume reduction surgery (change in forced expiratory volume in 1 sec, < 150 ml). The remaining five patients whose inspiratory resistance measurement was less than 8.5 cm H2O/l per second responded favorably to lung volume reduction surgery. Thus, only five of the 20 patients showed improvement in forced expiratory volume in 1 sec after surgery. CONCLUSION: Our data suggest that among patients with moderate to severe emphysema who are being examined for lung volume reduction surgery, the combination of radiologic and physiologic assessment is more accurate for predicting a favorable response to lung volume reduction surgery than radiologic assessment alone. However, in patients with chronic obstructive pulmonary disease by the American Thoracic Society criteria, mild emphysema as revealed on thin-section CT virtually precludes further workup because these patients are unlikely to respond favorably to lung volume reduction surgery.     

Dual isotope F-18 FDG and Tc-99m RBC imaging for lung cancer

PURPOSE: To produce fluorodeoxyglucose (FDG) images with markers for normal organs and large blood vessels in patients with suspected lung cancer. METHODS: Dual isotope SPECT images were made using F-18 FDG- and Tc-99m-labeled autologous red cells. RESULTS: FDG-positive lesions are localized in relation to major structures when they are viewed in a fused rotating three-dimensional display or in cross sections. CONCLUSIONS: Tc-99m red cell and FDG fusion imaging provides relative location information for lung tumors.     

Early dynamic SPECT acquisition for the imaging of hepatic hemangiomas utilizing Tc-99m labeled red blood cells

PURPOSE: To determine whether rapid, dynamic SPECT imaging with Tc-99m labeled red blood cells was technically feasible and of value in the detection of cavernous hemangiomas of the liver. MATERIALS AND METHODS: The acquisition protocol for Tc-99m labeled red blood cell imaging of hepatic hemangiomas was modified with six sequential 3-minute SPECT images replacing the planar flow phase. Delayed 20-minute SPECT of the liver was then performed 2 hours later. RESULTS: The authors present examples of pathologically proven positive and negative cases and retrospectively review their patient series. Examination of 19 patients with 41 lesions revealed no evidence of a false-positive examination results and only one false-negative result. Only one lesion seen to be positive with a 2-hour delayed study was not seen within 18 minutes. Lesions as small as 1.0 cm could be detected with a 3-minute SPECT. CONCLUSIONS: Rapid, dynamic early SPECT hemangioma imaging is feasible, provides images with relatively good quality, and can replace the planar flow phase.     

Radiologic emphysema morphology is associated with outcome after surgical lung volume reduction

BACKGROUND: Lung volume reduction surgery is known to alleviate dyspnea and to improve pulmonary function, performance in daily activity, and quality of life in selected patients with severe pulmonary emphysema. We investigated the role of radiologically assessed emphysema morphology on functional outcome after a lung volume reduction operation. METHODS: The preoperative chest computed tomograms in 50 consecutive patients who had undergone surgical lung volume reduction were retrospectively reviewed by 6 physicians blinded to the clinical outcome. Emphysema morphology was determined according to a simplified classification (ie, homogeneous, moderately heterogeneous, and markedly heterogeneous; lobe predominance). We studied the impact of these morphologic aspects on functional outcome at 3 months. RESULTS: We found a fair interobserver agreement applying our classification system. Functional improvement after surgical lung volume reduction was best in markedly heterogeneous emphysema with an increase in forced expiratory volume in 1 second of 81% +/- 17% (mean +/- standard error, n = 17) compared with 44% +/- 10% (n = 16) for intermediately heterogeneous emphysema. But also in patients with homogeneous emphysema clinical relevant improvement of function could be observed (increase in forced expiratory volume in 1 second = 34% +/- 6%; n = 17). CONCLUSIONS: The morphologic type of emphysema, assessed by a simplified surgically oriented classification, is an important predictor of surgical outcome. Lung volume reduction surgery may also improve dyspnea and lung function in homogeneous emphysema.     

MR analysis of lung volume and thoracic dimensions in patients with emphysema before and after lung volume reduction surgery

OBJECTIVE: This study was performed to assess the accuracy of determining lung volume in patients with emphysema using MR imaging and then to investigate changes in thoracic dimensions after lung volume reduction surgery. SUBJECTS AND METHODS: Fast gradient-echo breath-hold MR imaging through the entire thorax at full inspiration and expiration was performed in 21 patients with severe emphysema and was performed again in nine of the patients who underwent surgery. Lung volumes were determined using a semiautomated computerized method of delineating the lungs and summing cross-sectional areas. These summed areas were compared with volumes measured on plethysmography and CT. Postoperative changes in thoracic structure were determined by measuring anteroposterior and transverse lung dimensions and lung height before and after surgery. RESULTS: The correlation coefficients and SEM for determining inspiratory lung volume were MR imaging versus plethysmography, r = .77, SEM = -12% (volume measured as less on MR imaging); CT versus plethysmography, r = .86, SEM = -13% (volume measured as less on CT); and MR imaging versus CT, r = .87, SEM = 4% (volume measured as greater on MR imaging). The correlation coefficients and SEM for determining expiratory volume on MR imaging versus plethysmography were r = .77, SEM = 6% (volume measured as greater on MR imaging). After surgery, decreases were found in all thoracic dimensions, and such decreases were greatest at expiration. CONCLUSION: MR measurements of lung volume are comparable with those of CT and differ from those of plethysmography. Changes in thoracic dimensions after lung volume reduction surgery are consistent with improved respiratory mechanics.     

Changes in lung volume and volume of emphysema after unilateral lung reduction surgery: analysis with CT lung densitometry

PURPOSE: To evaluate changes in volume of the lungs and volume of emphysema after unilateral lung reduction surgery (ULRS) by using computed tomographic (CT) lung densitometry. MATERIALS AND METHODS: Twenty-eight patients underwent CT before and 3 months after ULRS. With use of a density mask software program and a three-dimensional graphics workstation, CT scans were analyzed to define the volume of the lungs and the volume of emphysema. Pre- and postoperative mean CT numbers were determined. RESULTS: After ULRS, the surgically reduced lung volume decreased 22%, and the intact opposite lung volume increased 4%. Emphysema in the surgically reduced lung decreased 14% and was unchanged in the intact opposite lung. Mean CT numbers in the surgically reduced lung increased 26 HU but were unchanged in the intact opposite lung. CONCLUSION: The effects of ULRS on each lung can be evaluated by using CT lung densitometry and a three-dimensional graphics workstation. ULRS reduces emphysema and lung volume in the surgically reduced lung without statistically significant worsening of contralateral emphysema at 3 months.     

Comparison of open and thoracoscopic bilateral volume reduction surgery: complications analysis

BACKGROUND: The effectiveness of lung volume reduction for the treatment of patients with emphysema is well established, but data about the surgical approach, the postoperative management, and complications are limited. We report a comparison of patients undergoing bilateral lung volume reduction (BLVRS) via median sternotomy and thoracoscopic techniques with emphasis on hospital course and complications. METHODS: All patients undergoing BLVRS at Hospital of University of Pennsylvania were analyzed for mortality and morbidity, using a combination of prospective data analysis and retrospective chart review. RESULTS: Patients undergoing BLVRS via median sternotomy were older than those undergoing video-assisted thoracoscopic surgery (VATS) procedures (63.9+/-6.89 vs 59.3+/-9.4 years, p = 0.005). Operating time was longer for the VATS procedure (147 versus 129 minutes, p = 0.006) while estimated blood less was greater for median sternotomy (209 versus 82 L, p = 0.0000017). Significant differences were found in intensive care unit stay, days intubated, life-threatening complications, respiratory complications, requirement for tracheostomy, and death that favored VATS BLVRS. When only later cohorts of patients were compared, more life-threatening complications and deaths were found in patients undergoing BLVRS by median sternotomy. There were no differences between early and late median sternotomy BLVRS patients. Twenty-six percent of the lethal complications in median sternotomy BLVRS patients were bowel perforations, equally divided between duodenal ulcers and colons. CONCLUSIONS: Managing patients after BLVRS remains complex. Bilateral video-assisted volume reduction offers equivalent functional outcome with potentially decreased morbidity and mortality. Gastrointestinal perforations can complicate the management of these patients.     

Volume reduction surgery in the native lung after single lung transplantation for emphysema

The natural history of emphysema suggests that progression of disease in the native lung may contribute to late deterioration in respiratory function after single lung transplantation. In this report, we describe our experience with unilateral volume reduction surgery in three single lung transplant recipients with emphysema. Each patient had had a late decline in lung function with a recurrence of symptoms. Chest radiographs demonstrated hyperinflation of the native lungs with encroachment on the grafts. Serial pulmonary function testing documented progressive reduction in expiratory flows with increases in residual volumes. Exercise testing confirmed severe intolerance to maximal exercise. Unilateral volume reduction surgery was undertaken at 36, 39, and 55 months after transplantation without incident. Radiographs obtained after the procedures demonstrated restoration of normal diaphragmatic contour, decreased aeration of the native lungs, and improved inflation of the allografts. Exercise testing at 3 months documented a mean improvement in maximal oxygen consumption of 35%. Expiratory flows improved by a mean of 60%. Quantitative ventilation and perfusion scans, however, were essentially unchanged. This experience suggests that unilateral volume reduction surgery may be considered as an alternative strategy in single lung transplant recipients with emphysema who exhibit clinically significant functional deterioration. Differentiation of the adverse effects of hyperinflation of the native lung from other potential causes of late deterioration might not be necessary but may be predictive of the degree of functional improvement after volume reduction. The relief of thoracic overdistention seems to play a primary role in the improvement pulmonary function.     

Accumulation of Tc-99m MIBI in breast lymphoma: comparison with Ga-67 citrate

We report 2 cases of malignant lymphoma of the breast which were clearly shown on total body imaging as well as on SPECT with Ga-67 and Tc-99m MIBI. Tumor accumulation of Ga-67 was seen in all cases including a recurrent tumor. Ga-67 scintigraphy is useful for follow up in detecting relapse, as well as in predicting responses to therapy. Tc-99m MIBI was found to accumulate in the malignant lymphoma of the breast, and especially SPECT images of breast lesions provided better contrast than planar images, and Tc-99m MIBI SPECT could diagnose localization of the tumor because there was no uptake by the breast. But the Tc-99m MIBI accumulation of the tumor was lower than Ga-67.     

Single-stage bilateral, video-assisted thoracoscopic lung volume reduction operation

Lung volume reduction (LVR) produces significant clinical and objective improvement in selected patients with diffuse emphysema. Unilateral and bilateral approaches have been successfully employed. A median sternotomy approach is the standard for bilateral LVR, whereas video-assisted thoracoscopy has been used to perform unilateral LVR. Encouraging video-assisted thoracoscopic results with sequential, staged, bilateral LVR have been shown. This report describes an alternate technique of single-stage, bilateral LVR for end-stage emphysema.     

Incremental value of prognostic testing in patients with known or suspected ischemic heart disease: a basis for optimal utilization of exercise technetium-99m sestamibi myocardial perfusion single-photon emission computed tomography

OBJECTIVES: This study assessed the incremental prognostic implications of normal and equivocal exercise technetium-99m (Tc-99m) sestamibi single-photon emission computed tomography (SPECT) and sought to determine its incremental prognostic value, impact on patient management and cost implications. BACKGROUND: The prognostic implications of Tc-99m sestamibi SPECT are not well defined, and risk stratification using this test has not been explored. METHODS: We studied 1,702 patients referred for exercise Tc-99m sestamibi SPECT who were followed up for a mean (+/- SD) of 20 +/- 5 months. Patients with previous percutaneous transluminal coronary angioplasty or coronary artery bypass surgery were excluded. The SPECT studies were assessed using semiquantitative visual analysis. Cardiac death and myocardial infarction were considered "hard" events, and coronary angioplasty and bypass surgery > 60 days after testing were considered "soft" events. RESULTS: Of the 1,702 patients studied, 1,131 had normal or equivocal scan results. A total of 10 events occurred in this group (1 cardiac death and 1 myocardial infarction [0.2% hard events]; 4 coronary angioplasty and 4 bypass surgery procedures [0.7% soft events]). The rates of hard events and referral to catheterization after SPECT were similarly low in patients with a low (< 0.15), intermediate (0.15 to 0.85) and high (> 0.85) post-exercise treadmill test (ETT) likelihood of coronary artery disease. With respect to scan type, patients with normal, probably normal or equivocal scan results had similarly low hard event rates. In the 571 patients with abnormal scan results, there were 43 hard events (7.5%) and 42 soft events (7.4%) (p < 0.001 vs. 1,131 patients with normal scan results for both). When the complete spectrum of scan responses was considered, SPECT provided incremental prognostic value in all patient subgroups analyzed. However, the nuclear scan was cost-effective only in patients with interpretable exercise ECG responses and an intermediate to high post-ETT likelihood of coronary artery disease and in those with uninterpretable exercise ECG responses and an intermediate to high pre-ETT likelihood of coronary artery disease. CONCLUSIONS: Normal or equivocal exercise Tc-99m sestamibi study results are associated with a benign prognosis, even in patients with a high likelihood of coronary artery disease. Although incremental prognostic value is added by nuclear testing in all patient subgroups, a testing strategy incorporating nuclear testing proved to be cost-effective only in the groups with an intermediate to high likelihood of coronary artery disease before scanning.     

Technetium-99m-MIBI and thallium-201 scintigraphy of primary lung cancer

We evaluated the usefulness of 99mTc-MIBI scintigraphy in primary lung cancer in comparison with 201Tl-chloride scintigraphy. METHODS: There were 45 patients with primary lung cancer. All patients underwent dual-isotope imaging with 201Tl-chloride and 99mTc-MIBI. Regions of interest were placed over the tumors (T) and contralateral normal lung tissue (N) on one coronal view in the SPECT, and T/N ratio and retention index were calculated. RESULTS: The positive rate was 98% in both the early and delayed images for 201Tl-chloride and 96% in the early and 89% in the delayed image for 99mTc-MIBI. Both early and delayed T/N ratios for 201Tl-chloride were higher than those for 99mTc-MIBI. There was no significant correlation between T/N ratio and histological type of tumor in both images. However, in both images, there was a tendency for the early and delayed ratios to increase as the tumor diameter became larger. The retention index of 201Tl-chloride was higher than that of 99mTc-MIBI. There were no significant differences in the retention index with respect to the histological type and tumor size. CONCLUSION: The results of this preliminary clinical study suggest that 99mTl-MIBI can depict primary lung cancer similar to 201Tl-chloride. However, T/N ratio and retention index of 99mTc-MIBI in the tumor areas are significantly lower compared with those of 201Tl-chloride.     

Interleukin-2 production by human pre-implantation embryos

We performed a double-phase Tc-99m-SestaMIBI SPECT study on a patient who presented with a mass located at the skull base. The results were compared with double-phase T1-201 SPECT study. Early phase (30 min) SPECT images of both radiopharmaceuticals demonstrated increased radiotracer uptake in the region of the tumor. However, late images (180 min) revealed rapid wash-out of Tc-99m-SestaMIBI from the tumor, suggestive of a benign vascular tumor, while T1-201 images showed slower wash-out. Tc-99m-SestaMIBI SPECT findings were also confirmed by carotid angiography and biopsy, while a contemporaneous MRI scan was inconclusive in differentiating benign from malignant tumor. Initial and one-year follow-up whole body CT scans were negative for any metastatic sites, supporting the diagnosis of benign glomus jugulare tumor.     

Diagnosis of right ventricular infarction by overlap images of simultaneous dual emission computed tomography using technetium-99m pyrophosphate and thallium-201

The validity of dual energy single-photon emission computed tomography (SPECT) with technetium-99m pyrophosphate (Tc-99m PPi) and thallium-201 for the diagnosis of right ventricular (RV) infarction, and the clinical features of RV infarction, were investigated in 190 patients with acute myocardial infarction. Diagnosis of RV infarction was performed by Tc-99m PPi accumulation in the RV myocardium on thallium-201 and Tc-99m PPi over-lay images at the dual SPECT with simultaneous imaging taken 2 to 9 days after the onset of myocardial infarction. Thirty RV infarctions were found among the 190 patients with left ventricular infarction (15.8%): 29 (97%) in association with the inferior and 1 (3%) with the lateral infarction. Tc-99m PPi accumulation was mostly observed in the posterior wall of the right ventricle. A total occlusion or a severe stenosis of the right coronary artery was demonstrated angiographically in 92% of the patients with RV infarction. The prevalence of RV infarctions was significantly lower in patients who achieved successful early reperfusion than in those who did not (26.7 vs 68.4%, respectively, p < 0.01). However, a successful early reperfusion therapy could not significantly decrease the rate of RV involvement in patients without significant collateral flow (p < 0.01). Thus, dual isotope SPECT with Tc-99m PPi and thallium-201 can be used as a reliable method for the diagnosis of RV infarction.     

HMPAO brain SPECT in acute carbon monoxide poisoning

Technetium-99m-hexamethylpropylene amine oxime (HMPAO) brain images with fanbeam SPECT, in combination with surface three-dimensional display, were used to detect basal ganglion and cerebral cortex anomalies in the acute phase of carbon monoxide (CO) poisoning. METHODS: Ten patients, aged 16-29 yr, with acute CO poisoning and no past history of neurologic disorders were enrolled in this study. After oxygen treatment, all 10 patients were investigated using 99mTc-HMPAO brain images with fanbeam SPECT and surface three-dimensional display. Meanwhile, 6 of 10 patients also received a brain CT scan. RESULTS: CT scan findings were negative in all 6 patients. Fanbeam SPECT demonstrated unilateral or bilateral hypoactivity of basal ganglia in 6 patients. Local hypoactivity anomalies were found in the brain cortex of 7 patients, using surface three-dimensional display of the brain. Only 2 of 10 patients had normal 99mTc-HMPAO brain images. CONCLUSION: This study suggests that, in comparison with traditional brain imaging techniques, 99mTc-HMPAO brain imaging with fanbeam SPECT in combination with surface three-dimensional display is a better tool for early detection of regional cerebral anomalies in acute CO poisoning.