• Title/Summary/Keyword: emission computed tomography

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Imaging Evaluation of Peritoneal Metastasis: Current and Promising Techniques

  • Chen Fu;Bangxing Zhang;Tiankang Guo;Junliang Li
    • Korean Journal of Radiology
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    • v.25 no.1
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    • pp.86-102
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    • 2024
  • Early diagnosis, accurate assessment, and localization of peritoneal metastasis (PM) are essential for the selection of appropriate treatments and surgical guidance. However, available imaging modalities (computed tomography [CT], conventional magnetic resonance imaging [MRI], and 18fluorodeoxyglucose positron emission tomography [PET]/CT) have limitations. The advent of new imaging techniques and novel molecular imaging agents have revealed molecular processes in the tumor microenvironment as an application for the early diagnosis and assessment of PM as well as real-time guided surgical resection, which has changed clinical management. In contrast to clinical imaging, which is purely qualitative and subjective for interpreting macroscopic structures, radiomics and artificial intelligence (AI) capitalize on high-dimensional numerical data from images that may reflect tumor pathophysiology. A predictive model can be used to predict the occurrence, recurrence, and prognosis of PM, thereby avoiding unnecessary exploratory surgeries. This review summarizes the role and status of different imaging techniques, especially new imaging strategies such as spectral photon-counting CT, fibroblast activation protein inhibitor (FAPI) PET/CT, near-infrared fluorescence imaging, and PET/MRI, for early diagnosis, assessment of surgical indications, and recurrence monitoring in patients with PM. The clinical applications, limitations, and solutions for fluorescence imaging, radiomics, and AI are also discussed.

Fusiform Aneurysm on the Basilar Artery Trunk Treated with Intra-Aneurysmal Embolization with Parent Vessel Occlusion after Complete Preoperative Occlusion Test

  • Jung, Young-Jin;Kim, Min-Soo;Choi, Byung-Yon;Chang, Chul-Hoon
    • Journal of Korean Neurosurgical Society
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    • v.53 no.4
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    • pp.235-240
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    • 2013
  • Fusiform aneurysms on the basilar artery (BA) trunk are rare. The microsurgical management of these aneurysms is difficult because of their deep location, dense collection of vital cranial nerves, and perforating arteries to the brain stem. Endovascular treatment is relatively easier and safer compared with microsurgical treatment. Selective occlusion of the aneurysmal sac with preservation of the parent artery is the endovascular treatment of choice. But, some cases, particularly giant or fusiform aneurysms, are unsuitable for selective sac occlusion. Therefore, endovascular coiling of the aneurysm with parent vessel occlusion is an alternative treatment option. In this situation, it is important to determine whether a patient can tolerate parent vessel occlusion without developing neurological deficits. We report a rare case of fusiform aneurysms in the BA trunk. An 18-year-old female suffered a headache for 2 weeks. Computed tomography and magnetic resonance image revealed a fusiform aneurysm of the lower basilar artery trunk. Digital subtraction angiography revealed a $7.1{\times}11.0$ mm-sized fusiform aneurysm located between vertebrovasilar junction and the anterior inferior cerebellar arteries. We had good clinical result using endovascular coiling of unruptured fusiform aneurysm on the lower BA trunk with parent vessel occlusion after confirming the tolerance of the patient by balloon test occlusion with induced hypotension and accompanied by neurophysiologic monitoring, transcranial Doppler and single photon emission computed tomography. In this study, we discuss the importance of preoperative meticulous studies for avoidance of delayed neurological deficit in the patient with fusiform aneurysm on lower basilar trunk.

Diagnosing Symptomatic Accessory Tarsal Bones Using SPECT/CT (SPECT/CT를 이용한 증후성 족부 부골의 진단)

  • Kim, Ryuh-Sup;Kang, Joon-Soon;Kim, Young-Tae;Kim, Bom-Soo
    • Journal of Korean Foot and Ankle Society
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    • v.15 no.4
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    • pp.212-216
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    • 2011
  • Purpose: This study was designed to analyze the usefulness of Single Photon Emission Computed Tomography/Computed Tomography (SPECT/CT) in diagnosing symptomatic accessory tarsal bones. Materials and Methods: Twenty four feet (16 patients) with symptomatic accessory navicular and/or os trigonum, who agreed to take SPECT/CT, were included in this study. Fifteen feet had accessory navicular, five had os trigonum, and four had both. According to the uptake in the SPECT/CT, 11 feet were classified into high and 13 into low uptake groups. The low uptake group was treated non-operatively, while the high uptake group received operations when initial conservative management failed. A modified Kidner procedure was performed for accessory navicular and arthroscopic excision was done for os trigonum. After a mean follow-up of 6.8 (range, 3~13) months, the American Orthopaedic Foot and Ankle Society (AOFAS) score and the Visual Analogue Scale (VAS) for pain were compared. Results: Patients in the high uptake group had a higher initial mean VAS score ($7.0{\pm}0.8$ vs $2.2{\pm}0.9$, p<0.05) and a lower initial mean AOFAS score ($45.9{\pm}9.2$ vs $83.9{\pm}4.2$, p<0.05) compared to the low uptake group. All patients in the low uptake group improved after non-operative treatment. Seven patients underwent operations and had a decreased VAS ($1.6{\pm}0.5$) and an increased AOFAS score ($88.3{\pm}1.8$) at the last follow-up. Four patients in the high uptake group demonstrated erratic symptoms. Conclusion: SPECT/CT can be a useful diagnostic tool and helpful in designing treatment plans for symptomatic accessory navicular and os trigonum.

Associations between Brain Perfusion and Sleep Disturbance in Patients with Alzheimer's Disease

  • Im, Jooyeon J.;Jeong, Hyeonseok S.;Park, Jong-Sik;Na, Seung-Hee;Chung, Yong-An;Yang, YoungSoon;Song, In-Uk
    • Dementia and Neurocognitive Disorders
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    • v.16 no.3
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    • pp.72-77
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    • 2017
  • Background and Purpose Although sleep disturbances are common and considered a major burden for patients with Alzheimer's disease (AD), the fundamental mechanisms underlying the development and maintenance of sleep disturbance in AD patients have yet to be elucidated. The aim of this study was to examine the correlation between regional cerebral blood flow (rCBF) and sleep disturbance in AD patients using technetium-99m hexamethylpropylene amine oxime single-photon emission computed tomography (SPECT). Methods A total of 140 AD patients were included in this cross-sectional study. Seventy patients were assigned to the AD with sleep loss (SL) group and the rest were assigned to the AD without SL group. SL was measured using the sleep subscale of the Neuropsychiatric Inventory. A whole-brain voxel-wise analysis of brain SPECT data was conducted to compare the rCBF between the two groups. Results The two groups did not differ in demographic characteristics, severity of dementia, general cognitive function, and neuropsychiatric symptoms, with the exception of sleep disturbances. The SPECT imaging analysis displayed decreased perfusion in the bilateral inferior frontal gyrus, bilateral temporal pole, and right precentral gyrus in the AD patients with SL group compared with the AD patients without SL group. It also revealed increased perfusion in the right precuneus, right occipital pole, and left middle occipital gyrus in the AD with SL group compared with the AD without SL group. Conclusions The AD patients who experienced sleep disturbance had notably decreased perfusion in the frontal and temporal lobes and increased rCBF in the parietal and occipital regions. The findings of this study suggest that functional alterations in these brain areas may be the underlying neural correlates of sleep disturbance in AD patients.

The acupuncture mechanism related brain in Medline and the journal of Korean acupuncture & moxibustion (PubMed와 대한침구학회지(大韓針灸學會誌) 논문(論文) 검색(檢索)을 통(通)한 침요법(鍼療法)과 뇌(腦)와의 관계(關係)에 대한 연구동향(硏究動向) 고찰(考察))

  • Kim, Hoo-Dong;Koh, Hyung-Kyun;Kim, Chang-Hwan
    • Journal of Acupuncture Research
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    • v.18 no.4
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    • pp.188-200
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    • 2001
  • Background and Objetive : Acupuncture is a valuable method of oriental medicine with broad application in many disease. It is based on the experiences of traditional oriental medicine as well as on experimentally proven biological (biochemical and neurophysiological) effects. Acupuncture theory has been explained by the meridian system that is thought to be linked with particular organs. However, in western medicine it is held that many disorders are either controlled or affected by the brain. Material and Method : In order to review the studies concerned with the mechanism related brain, we have referred to the Pubmed site and the Journal of Korean acupuncture and moxibustion Result and Conculsion : Among the 12 studies in the Journal of Korean acupuncture and moxibustion, 8 papers related neurotransmitters were done by experimental study, 4 papers related brain mapping were done by clinical study. Among the 8 studies related brain mapping in the Pubmed site, 6 clinical studies using functional magnetic resonance imaging(fMRI) were done and I clinical study using single-photon emission computed tomography(SPECT) was done, I paper was review article. By the above result, it would be needed further research on the acupuncture mechanism related brain using SPECT, fMRI, positron emission tomography(PET) etc.

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Recent Advances in Nuclear Medicine Imaging Instrumentation (핵의학 영상기기의 최근 진보)

  • Jung, Jin-Ho;Choi, Yong;Hong, Key-Jo;Min, Byung-Jun;Hu, Wei;Kang, Ji-Hoon
    • 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.

Evaluation of Merkel Cell Carcinoma Metastasis Using Positron Emission Topography/CT (양전자방출단층촬영술(PET/CT)을 이용한 메르켈 세포암(Merkel cell carcinoma)의 전이 평가)

  • Kwon, Soon Hong;Song, Jin Kyung;Yoo, Gyeol;Byeon, Jun Hee
    • Archives of Plastic Surgery
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    • v.33 no.2
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    • pp.233-236
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    • 2006
  • Merkel cell carcinoma is rare skin malignancy originated from epidermal mechanoreceptor of neural origin. The tumor usually affects older individuals at sun exposed area such as head, neck and extremity. Subclinical involvement of regional lymph node is reported frequently at the time of initial treatment. Thus even asymptomatic patients who present with clinically localized tumor should undergo evaluation with computed tomography and lymphangiography. Positron emission tomography(PET) scans can imaging the metabolic difference of malignant tumors. Increased glucose uptake of malignant tumor cells are detected by PET scanner. PET scans can provide qualitative and quantitative informations about systemic metastasis of tumors. Although there are no data that define the efficacy of PET scans in the initial diagnostic evaluation of head and neck cancer, they could be considered. Current standards of treatment of Merkel cell carcinoma is wide surgical excision and regional lymphadenectomy if there are suspicious lymph nodes. The author reported a patient with Merkel cell carcinoma of cheek. Wide surgical excision and postoperative PET/CT was done for evaluation of regional lymph node and distant metastasis. There were two hot-uptakes in patient's neck, so they were considered as metastatic node, but finally they were proved to be tuberculosis lymphadenitis after excision.

The Lowest Dose for CT Attenuation Correction in PET/CT

  • Kang, Byung-Sam;Son, Jin-Hyun;Park, Hoon-Hee;Dong, Kyung-Rae
    • Korean Journal of Digital Imaging in Medicine
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    • v.13 no.3
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    • pp.111-115
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    • 2011
  • PET/CT(Positron Emission Tomography/Computed Tomography) is an examination combining morphological and functional information in one examination. The purpose of this study is to see the lowest CT dose for attenuation correction in the PET/CT maintaining good image quality when considering CT scan dose to the patients. We injected $^{18}F$-FDG and water into the cylinder shaped phantom, and obtained emission images for 3 mins and transmission images(140 kVp, 8 sec, 10~200 mA for transmission images), and reconstructed the images to PET/CT images with Iterative method. Data(Maximum, Minimum, Average, Standard Deviation) were obtained by drawing a circular ROI(Region Of Interest) on each sphere in each image set with Image J program. And then described SD according to the CT and PEC/CT images as graphes. Through the graphes, we got the relationships of mA and quality of images. SDs according to CT graph were 16.25 at 10 mA, 7.26 at 50 mA, 5.5 at 100 mA, 4.29 at 150 mA, and 3.83 at 200 mA, i.e. the higer mA, the better image quality was presented. SDs according to PET/CT graph were 1823.2 at 10 mA, 1825.1 at 50 mA, 1828.4 at 100 mA, 1813.8 at 150 mA, and 1811.3 at 200 mA. Calculated SDs at PET/CT images were maintained. This means images quality is maintained having nothing to do with mA of high and low.

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Pulling Bowstring of Gated Myocardial SPECT (게이트 심근 SPECT : 도약을 위한 준비)

  • Bom, Hee-Seung
    • The Korean Journal of Nuclear Medicine
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    • v.32 no.5
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    • pp.433-435
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    • 1998
  • Recent progress of technology permits us to assess ventricular function and wall motion as well as myocardial perfusion using electrocardiographic gated myocardial perfusion single photon emission computed tomography (GM-SPECT). It is interesting that echocardiography and magnetic resonance imaging are moving in the same direction with the use of contrast medium to assess myocardial perfusion. A valid fundamental basis for a new technology is essential for a successful competition. Lee et al. report in this issue the reproducibility of serial measurement of left ventricular function including systolic wall thickening using a novel statistical method. It has important implications such as nitroglycerin or dobutamine application during GM-SPECT. The field of nuclear cardiology must continue to strive toward more sophisticated but straightforward evaluation of cardiac diseases.

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Accumulation of Thallium-201 in Hemorrhagic Cerebral Infarction (Thallium-201 brain SPECT에서 양성 소견을 보인 출혈성 뇌경색)

  • Lee, Ki-Yeol;Kim, Kyung-Min;Choe, Jae-Gol;Chung, Yong-Gu
    • The Korean Journal of Nuclear Medicine
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    • v.33 no.3
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    • pp.337-340
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    • 1999
  • Thallium-201 brain SPECT is utilized in the diagnosis of brain tumor especially in cases where CT or MRI findings alone cannot differentiate malignant lesion from benign. Recently we came across two cases of positive T1-201 brain SPECT in clinically suspected brain tumor patients that turned out to be hemorrhagic cerebral infarction instead on biopsy. The findings in these cases demonstrate that thallium-201 accumulation may occur by the breakdown of the blood-brain barrier and phagocytic cell infiltration in the liquefaction stage of infarction.

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