• The Korean Journal of Nuclear Medicine Technology
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• v.22 no.1
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• pp.90-97
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• 2018

Purpose The lung segment ratio which is obtained through quantitative analyses of lung perfusion scan images is calculated to evaluate the lung function pre and post surgery. In this Study, the planar image production methods by using Q-Metrix (GE Healthcare, USA) program capable of not only quantitative analysis but also computation of the segment ratio after having performed SPECT/CT are comparatively evaluated. Materials and Methods Lung perfusion scan and SPECT/CT were performed on 50 lung cancer patients prior to surgery who visited our hospital from May 1, 2015 to September 13, 2016 by using Discovery 670(GE Healthcare, USA) equipment. AP(Anterior Posterior)method that uses planar image divided the frontal and rear images into three rectangular portions by means of ROI tool while PO(Posterior Oblique)method computed the segment ratio by dividing the right lobe into three parts and the left lobe into two parts on the oblique image. Segment ratio was computed by setting the ROI and VOI in the CT image by using Q-Metrix program and statistically analysis was performed with SPSS Ver. 23. Results Regarding the correlation concordance rate of Q-Metrix and AP methods, RUL(Right upper lobe), RML(Right middle lobe) and RLL(Right lower lobe) were 0.224, 0.035 and 0.447. LUL(Left upper lobe) and LLL(Left lower lobe) were found to be 0.643 and 0.456, respectively. In the PO method, the right lobe were 0.663, 0.623 and 0.702, respectively, while the left lobe were 0.754 and 0.823. When comparison was made by using the Paired sample T-test, Right lobe were $11.6{\pm}4.5$, $26.9{\pm}6.2$ and $17.8{\pm}4.2$, respectively in the AP method. Left lobe were $28.4{\pm}4.8$ and $15.4{\pm}5.6$. The right lobe of PO had values of $17.4{\pm}5.0$, $10.5{\pm}3.6$ and $27.3{\pm}6.0$, while the left lobe had values of $21.6{\pm}4.8$ and $23.1{\pm}6.6$, thereby having statistically significant difference in comparison to the Q-Metrix method for each of the lobes (P<0.05). However, there was no statistically significant difference in Right middle lobe (P>0.05). Conclusion The AP method showed low concordance rate in correlation with the Q-Metrix method. However, PO method displayed high concordance rate overall. although AP method had significant differences in all lobes, there was no significant difference in Right middle lobe of PO method. Therefore, at the time of production of lung perfusion scan results, utilization of Q-Metrix method of SPECT/CT would be useful in computation of accurate resultant values. Moreover, it is deemed possible to expect obtain more practical sectional computation result values by using PO method at the time of planar image acquisition.

• The Korean Journal of Nuclear Medicine
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• v.39 no.4
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• pp.246-251
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• 2005

Purpose: There has been many reports for the effect of attenuation correction on myocardial perfusion SPECT. We studied the effect of attenuation correction with CT (computed tomography) in patients with normal coronary angiography. Materials and Methods: Fifteen patients with normal coronary artery on angiography and low likelihood of coronary artery disease were enrolled in this study (male: 6, female: 9, mean age: $58{\pm}8$ year). Myocardial perfusion SPECT was done with Millennium VG with Hawkeye device (GE, SPECT/CT camera). A visual analysis and polar map quantification (Emory tool box) was performed. In quantitative analysis, percent uptake of each myocardial wall on polar map (percent of maximal uptake) was compared between non-corrected (NC) and corrected (AC) images. Results: Visual analysis showed AC images led to an increase of uptake in the inferior wall, but decrease of uptake in the anterior wall, apex and septum. liver activity is also increased in AC images. In quantitative analysis, the percent uptake is decreased in the anterior wall, apex and septum, but increased in the inferior wall. It is helpful to interpret the images in the inferior wall after AC, but difficult in the apex and anterior wall after AC. Conclusion: AC is helpful in the inferior wall. But in the apex or anterior wall, AC must be carefully applied to normal perfused myocardium.

• Korean Journal of Radiology
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• v.22 no.3
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• pp.395-404
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• 2021

Objective: To compare the utility of computed tomography perfusion (CTP) and three different 4-point scoring systems in computed tomography angiography (CTA) in confirming brain death (BD) in patients with and without skull defects. Materials and Methods: Ninety-two patients clinically diagnosed as BD using CTA and/or CTP for confirmation were retrospectively reviewed. For the final analysis, 86 patients were included in this study. Images were re-evaluated by three radiologists according to the 4-point scoring systems that consider the vessel opacification on 1) the venous phase for both M4 segments of the middle cerebral arteries (MCAs-M4) and internal cerebral veins (ICVs) (A60-V60), 2) the arterial phase for the MCA-M4 and venous phase for the ICVs (A20-V60), 3) the venous phase for the ICVs and superior petrosal veins (ICV-SPV). The CTP images were independently reviewed. The presence of an open skull defect and stasis filling was noted. Results: Sensitivities of the ICV-SPV, A20-V60, A60-V60 scoring systems, and CTP in the diagnosis of BD were 89.5%, 82.6%, 67.4%, and 93.3%, respectively. The sensitivity of A20-V60 scoring was higher than that of A60-V60 in BD patients (p < 0.001). CTP was found to be the most sensitive method (86.5%) in patients with open skull defect (p = 0.019). Interobserver agreement was excellent in the diagnosis of BD, in assessing A20-V60, A60-V60, ICV-SPV, CTP, and good in stasis filling (κ: 0.84, 0.83, 0.83, 0.83, and 0.67, respectively). Conclusion: The sensitivity of CTA confirming brain death differs between various proposed 4-point scoring systems. Although the ICV-SPV is the most sensitive, evaluation of the SPV is challenging. Adding CTP to the routine BD CTA protocol, especially in cases with open skull defect, could increase sensitivity as a useful adjunct.

• The Korean Journal of Nuclear Medicine Technology
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• v.17 no.2
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• pp.78-83
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• 2013

Purpose: SPECT/CT, a combination of SPECT and CT, is capable of expressing the results of attenuation correction on images biased by automatic program. As a result, this research evaluates the usefulness of images with CT attenuation correction, using various phantoms and images of patients. Materials and Methods: From July of 2012 to September of 2012, this research was conducted on the contrast, spatial resolution, and images of patients. We studied the contrast with IEC body phantom and Jaszczak phantom, while the spatial resolution was evaluated with NEMA triple line phantom. Further, a comparative study was carried out on the quality of the images, on the difference between the images before and after the CT attenuation correction. Results: Compared the differences between the contrast before and after the CT attenuation correction in IEC body phantom. The contrast was improved by 33.6% at minimum, 89.8% at maximum. In case of Jaszczak Phantom, the contrast was enhanced by 9.9% at minimum, 27.8% at maximum. In NEMA Triple line phantom, the resolution was raised by 4.5% in average: 4.4% in horizontal, 4.5% in vertical. In Anthropomorphic Torso Phantom, the perfusion score of the interior wall with the most severe attenuation was measured to be 29.4%. In the experiment carried out on myocardial perfusion SPECT/CT patients, 9% improvement was discovered in the interior wall, where the most dramatic attenuation occurred, after the CT attenuation correction. Conclusion: SPECT/CT proved its clinical usefulness by enabling the acquisition of images with enhanced contrast and spatial resolution compare to the ones resulted from SPECT.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.16
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• pp.6565-6570
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• 2014

Objective: To observe the curative effects of rh-endostatin combined with DP regimen in treating patients with advanced esophageal cancer and analyze the correlation of CT perfusion (CTP) parameters and the expression of vascular endothelial growth factor (VEGF). Methods: Twenty patients with esophageal cancer confirmed pathologically were randomly divided into combined treatment (rh-endostatin+DP regimen) group and single chemotherapy group, 10 patients in each group, respectively. All patients were given conventional CT examination and CTP imaging for primary tumor. The level of VEGF, the size of tumor and CTP parameters (BF, BV, PS and MTT) before treatment and after 2 cycles of treatment were determined for the comparison and the correlation between CTP parameters and VEGF expression was analyzed. Results: the therapeutic effect of rh-endostatin+DP regimen group was superior to single chemotherapy group. VEGF level after treatment in rh-endostatin+DP regimen group was obviously lower than single chemotherapy group (P<0.01). The expression of VEGF had positive correlation with BF and BV but negative correlation with MTT. Compared with treatment before for rh-endostatin+DP regimen group, BF, BV and PS decreased while MTT increased after treatment (P<0.05). However, there were no significant differences between treatment before and after treatment in single chemotherapy (P>0.05). Conclusions: Rh-endostatin can down-regulate the expression of VEGF in esophageal cancer, change the state of hypertransfusion and high permeability of tumor vessels and had the better curative effect and slighter adverse reactions when combined with chemotherapy.

• The Korean Journal of Nuclear Medicine
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• v.35 no.4
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• pp.241-250
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• 2001

Purpose: Vasospasm is a complication of aneurysmal subarachnoid hemorrhage (aSAH). We assessed the role of acetazolamide-enhanced brain perfusion SPECT (ACZ-SPECT) with Tc-99m ECD for predicting the prognosis of patients with aSAH. Materials and methods: Two SPECT studios (baseline with 740 MBq and ACZ-SPECT with 1480 MBq) with image subtraction were performed in 21 patients with aSAH. All patients had brain CT and angiogram. Vasoreactivity on ACZ-SPECT, perfusion defect on baseline SPECT, and vasospasm on angiogram were correlated with Hunt-Hess grading, extent of SAH (unilateral or bilateral) on CT, and clinical outcome. Vasoreactivity was considered decreased when cerebral/cerebellar uptake ratio difference from baseline SPECT to ACZ-SPECT was greater than 2SD of normal control values. Results: Decreased vasoreactivity was observed in 38% (8/21), perfusion defect in 81% (17/21), and vasospasm in 38% (8/21). The preserved vasoreactivity group showed better outcome scale (92%, 12/13) and the decreased vasoreactivity group showed poorer outcome scale (62.5%, 5/8) (p=0.014). Extensive SAH was more frequently seen in the decreased vasoreactlvlty group (87.5%, 7/8) than in the preserved vasoreactivity group (30.7%, 4/13)(p=0.017). The perfusion defect and vasospasm did not show good correlation with outcome scale, extent of SAH, and Hunt-Hess grading (p=ns). Vasoreactivity represented the patient's outcome better than the vasospasm in all of the vasoreactivity/vasospasm-mismatched cases (6 cases). Conclusions: Our data show that decreased vasoreactivity on ACZ-SPECT does not always represent vasospastic condition. But patients with decreased vasoreactivity reveal poorer outcome than patients with angiographic vasospasm do. Therefore ACZ-SPECT is a valuable, noninvasive test for predicting the prognosis of patients with aSAH.

• Nuclear Medicine and Molecular Imaging
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• v.43 no.6
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• pp.513-518
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• 2009

Purpose: Integration of the functional information of myocardial perfusion SPECT (MPS) and the morphoanatomical information of coronary CT angiography (CTA) may provide useful additional diagnostic information of the spatial relationship between perfusion defects and coronary stenosis. We studied to know the added value of three dimensional cardiac SPECT/CTA fusion imaging (fusion image) by comparing between fusion image and MPS. Materials and Methods: Forty-eight patients (M:F=26:22, Age: $63.3{\pm}10.4$ years) with a reversible perfusion defect on MPS (adenosine stress/rest SPECT with Tc-99m sestamibi or tetrofosmin) and CTA were included. Fusion images were molded and compared with the findings from the MPS. Invasive coronary angiography served as a reference standard for fusion image and MPS. Results: Total 144 coronary arteries in 48 patients were analyzed; Fusion image yielded the sensitivity, specificity, negative and positive predictive value for the detection of hemodynamically significant stenosis per coronary artery 82.5%, 79.3%, 76.7% and 84.6%, respectively. Respective values for the MPS were 68.8%, 70.7%, 62.1% and 76.4%. And fusion image also could detect more multi-vessel disease. Conclusion: Fused three dimensional volume-rendered SPECT/CTA imaging provides intuitive convincing information about hemodynamic relevant lesion and could improved diagnostic accuracy.

• Journal of Yeungnam Medical Science
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• v.26 no.1
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• pp.15-23
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• 2009

Constant technological developments in coronary artery disease have contributed to the assessment of both the presence of coronary stenosis and its hemodynamic consequences. Hence, noninvasive imaging helps guide therapeutic decisions by providing complementary information on coronary morphology and on myocardial perfusion and metabolism. This can he done using single photon emission computed tomography (SPECT) or positron emission tomography (PET) and multidetector CT (MDCT). Advances in image-processing software and the advent of SPECT/CT and PET/CT have paved the way for the combination of image datasets from different modalities, giving rise to hybrid imaging. Three dimensional cardiac hybrid imaging helped to confirm hemodynamic significance in many lesions, add new lesions such as left main coronay artery disease, exclude equivocal defects, correct the corresponding arteries to their allocated defects and identify culprit segment. Cardiac hybrid imaging avoids the mental integration of functional and morphologic images and facilitates a comprehensive interpretation of coronaty lesions and their pathophysiologic adequacy by three dimensional display of fused images, and allows the best evaluation of myocardial territories and the coronary-artery branches that serve each territory. This integration of functional and morphological information were feasible to intuitively convincing and might facilitate development of a comprehensive non-invasive assessment of coronary artery disease.

• Nuclear Medicine and Molecular Imaging
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• v.43 no.3
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• pp.159-164
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• 2009

Coronary artery disease is on the rise over the world. Myocardial perfusion SPECT is a well established technique to detect coronary artery disease and to assess left ventricular function. In addition, it has the unique ability to predict the prognosis of the patients. Moreover, the application of ECC-gated images provided the quantitatve data and improved the accuracy. This approach has been proved to be cost-effective and suitable for the emerging economies as well as developed countries. However, the utilization of nuclear cardiology procedures vary widely considering the different countries and region of the world. Korea exits 2-3 times less utilization than Japan, and 20 times than the United States. Recently, with the emerging of new technology, namely cardiac CT, cardiac MR and stress echocardiography, the clinical usefulness of nuclear cardiology has been called in question and its role has been redefined. For the proper promotion of nuclear cardiology, special educations should be conducted since the nuclear cardiology has the contact points between nuclear medicine and cardiology. Several innovations are in horizon which will impact the diagnostic accuracy as well as imaging time and cost savings. Development of new tracers, gamma camera technology and hybrid systems will open the new avenue in cardiac imaging. The future of nuclear cardiology based on molecular imaging is very exciting. The newly defined biologic targets involving atherosclerosis and vascular vulnerability will allow the answers for the key clinical questions. Hybrid techniques including SPECT/CT indicate the direction in which clinical nuclear cardiology may be headed in the immediate future. To what extent nuclear cardiology will be passively absorbed by other modalities, or will actively incorporate other modalities, is up to the present and next generation of nuclear cardiologists.

• Nuclear Medicine and Molecular Imaging
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• v.42 no.2
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• pp.98-111
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• 2008

This review introduces advances in clinical and pre-clinical single photon emission computed tomography (SPECT) and positron emission tomography (PET) providing noninvasive functional images of biological processes. Development of new collimation techniques such as multi-pinhole and slit-slat collimators permits the improvement of system spatial resolution and sensitivity of SPECT. Application specific SPECT systems using smaller and compact solid-state detector have been customized for myocardial perfusion imaging with higher performance. Combined SPECT/CT providing improved diagnostic and functional capabilities has been introduced. Advances in PET and CT instrumentation have been incorporated in the PET/CT design that provide the metabolic information from PET superimposed on the anatomic information from CT. Improvements in the sensitivity of PET have achieved by the fully 3D acquisition with no septa and the extension of axial field-of-view. With the development of faster scintillation crystals and electronics, time-of-flight (TOF) PET is now commercially available allowing the increase in the signal-to-noise ratio by incorporation of TOF information into the PET reconstruction process. Hybrid PET/SPECT/CT systems has become commercially available for molecular imaging in small animal models. The pre-clinical systems have improved spatial resolution using depth-of-interaction measurement and new collimators. The recent works on solid state detector and dual modality nuclear medicine instrumentations incorporating MRI and optical imagers will also be discussed.