• Nuclear Medicine and Molecular Imaging
• /
• 제42권2호
• /
• pp.98-111
• /
• 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.

• 디지털융복합연구
• /
• 제17권4호
• /
• pp.177-185
• /
• 2019

본 연구는 인체 골격의 좌표형 임상용어체계 표준을 개발하기 위한 방법론적 연구이다. 문헌고찰과 자료 수집을 통해 연구 계획을 수립하여 예비 표준(안)을 만들고 전문가 세미나와 자문을 통해 수정 표준(안)을 만든 후 내용타당도 검증 후 최종(안)을 제시하는 4단계를 거쳐 표준을 개발하였다. 좌표형 임상용어체계 표준은 인체 이미지를 2D는 x, y축, 3D는 x,y,z축으로 좌표화하고, 좌표의 개념과 정의는 SNOMED CT의 FSN, Synonym, Preferred name으로 선조합하고 후조합은 개발 된 18개의 Relationship을 통해 정의되고, 개발된 Relationship 표준의 내용타당도 지수는 평균 4.01점이었다. 본 연구를 통해 인체 골격 이외의 뇌, 장기, 조직 등의 인체의 다른 부분에 대한 후속 표준 개발을 제언하고 임상에서 활용성을 높이기 위한 방법 연구를 제언한다.

• Korean Journal of Radiology
• /
• 제21권8호
• /
• pp.998-1006
• /
• 2020

Objective: To compare the accuracies of quantitative computed tomography (CT) parameters and semiquantitative visual score in evaluating clinical classification of severity of coronavirus disease (COVID-19). Materials and Methods: We retrospectively enrolled 187 patients with COVID-19 treated at Tongji Hospital of Tongji Medical College from February 15, 2020, to February 29, 2020. Demographic data, imaging characteristics, and clinical data were collected, and based on the clinical classification of severity, patients were divided into groups 1 (mild) and 2 (severe/critical). A semiquantitative visual score was used to estimate the lesion extent. A three-dimensional slicer was used to precisely quantify the volume and CT value of the lung and lesions. Correlation coefficients of the quantitative CT parameters, semiquantitative visual score, and clinical classification were calculated using Spearman's correlation. A receiver operating characteristic curve was used to compare the accuracies of quantitative and semi-quantitative methods. Results: There were 59 patients in group 1 and 128 patients in group 2. The mean age and sex distribution of the two groups were not significantly different. The lesions were primarily located in the subpleural area. Compared to group 1, group 2 had larger values for all volume-dependent parameters (p < 0.001). The percentage of lesions had the strongest correlation with disease severity with a correlation coefficient of 0.495. In comparison, the correlation coefficient of semiquantitative score was 0.349. To classify the severity of COVID-19, area under the curve of the percentage of lesions was the highest (0.807; 95% confidence interval, 0.744-0.861: p < 0.001) and that of the quantitative CT parameters was significantly higher than that of the semiquantitative visual score (p = 0.001). Conclusion: The classification accuracy of quantitative CT parameters was significantly superior to that of semiquantitative visual score in terms of evaluating the severity of COVID-19.

• 대한미생물학회지
• /
• 제34권6호
• /
• pp.513-518
• /
• 1999

A total of 113 Vibrio sp. strains were examined for plasmid content which were subjected to digestion with restriction enzymes. About the 55% Vibrio spp. have the plasmid more than one. Most of these plasmid various derivatives ranged from $2.4\;kb{\sim}23\;kb$, especially two strains of V. mimicus and one strain of V. furnissii carried one high-molecular weight plasmid (molecular weight ranging between $70\;kb{\sim}100\;kb$). Results of restriction analysis for plasmid of this three strains were by no means the rule. For detection of tdh and ctx gene, the virulence factor involved in the pathogenesis, we carried out the TDH and CT assay, PCR amplification, and hybridization. A total 11 strains were produced TDH, involved in 9 strains of V. parahaemolyticus and 1 strain of V. alginolyticus from clinical isolates and 1 strains of V. mimicus from environmental isolates. In the experiments of tdh gene detection, in all, 3 strains of V. parahaemolyticus from clinical isolates and 2 strains from environmental isolates could be successfully amplified in 400 bp by PCR. The PCR results were consistent with DNA hybridization tests. In the experiments of CT assay, in all, 3 strains of V. cholerae from clinical isolate and 1 strain of V. cholerae from environmental isolates were observed CT-producing. These CT-producing strains amplified in 302 bp by PCR for the detection of ctx gene. All CT-producing strains hybridized with digoxigenin-labeled DNA probe, while CT-negative strains did not hybridize. Also hybridization tests results for detection of ctx gene consistent with PCR.

• Asian Pacific Journal of Cancer Prevention
• /
• 제14권3호
• /
• pp.1649-1654
• /
• 2013

Objective: This work aimed to evaluate the safety and clinical efficacy of transcatheter arterial chemoembolization (TACE) combined with c-arm cone-beam CT guided synchronous radiofrequency ablation (RFA) in treatment of large hepatocellular carcinoma (HCC). Methods: 21 patients with large HCC were studied from January 2010 to March 2012. TACE combined with synchronous C-arm cone-beam CT guided RFA were performed on a total of 25 lesions. Conventional imaging examination (CEUS, enhanced CT or MRI) and AFP detection were regularly conducted to evaluate the technical success rate of combined treatment, complications, treatment response, time without disease recurrence and survival rate. Results: The technical success rate of combined treatment was 100%, without any significant complication. After 1 month, there were 19 cases with complete response and 2 cases with partial response, with an complete response rate of 90.4% (19/21) and a clinical effective rate of 100% (21/21). The complete response rates of single nodular lesions (100%, 17/17) was significantly higher than that of multiple nodular lesions (50%, 2/4) (P<0. 05). During 2 to 28 months of follow-up, in 19 cases with complete response, the average time without disease recurrence was $10.8{\pm}6$ months. The total survival rates of 6, 12 and 18 months in 21 patients were 100%, respectively. Conclusion: TACE combined with synchronous C-arm CT guided RFA is safe and effective for treatment of large HCC. The treatment efficacy for single nodular lesion is better than that for multiple nodular lesions.

• Korean Journal of Radiology
• /
• 제24권6호
• /
• pp.529-540
• /
• 2023

Objective: To compare the diagnostic performance and clinical outcomes of 2-mSv computed tomography (CT) and conventional-dose CT (CDCT), following radiology residents' interpretation of CT examinations for suspected appendicitis. Materials and Methods: Altogether, 3074 patients with suspected appendicitis aged 15-44 years (28 ± 9 years, 1672 females) from 20 hospitals were randomly assigned to the 2-mSv CT (n = 1535) or CDCT (n = 1539) groups in a pragmatic trial from December 2013 and August 2016. Overall, 107 radiology residents participated in the trial as readers in the form of daily practice after online training for 2-mSv CT. They made preliminary CT reports, which were later finalized by attending radiologists via addendum reports, for 640 and 657 patients in the 2-mSv CT and CDCT groups, respectively. We compared the diagnostic performance of the residents, discrepancies between preliminary and addendum reports, and clinical outcomes between the two groups. Results: Patient characteristics were similar between the 640 and 657 patients. Residents' diagnostic performance was not significantly different between the 2-mSv CT and CDCT groups, with a sensitivity of 96.0% and 97.1%, respectively (difference [95% confidence interval {CI}], -1.1% [-4.9%, 2.6%]; P = 0.69) and specificity of 93.2% and 93.1%, respectively (0.1% [-3.6%, 3.7%]; P > 0.99). The 2-mSv CT and CDCT groups did not significantly differ in discrepancies between the preliminary and addendum reports regarding the presence of appendicitis (3.3% vs. 5.2%; -1.9% [-4.2%, 0.4%]; P = 0.12) and alternative diagnosis (5.5% vs. 6.4%; -0.9% [-3.6%, 1.8%]; P = 0.56). The rates of perforated appendicitis (12.0% vs. 12.6%; -0.6% [-4.3%, 3.1%]; P = 0.81) and negative appendectomies (1.9% vs. 1.1%; 0.8% [-0.7%, 2.3%]; P = 0.33) were not significantly different between the two groups. Conclusion: Diagnostic performance and clinical outcomes were not significantly different between the 2-mSv CT and CDCT groups following radiology residents' CT readings for suspected appendicitis.

• Radiation Oncology Journal
• /
• 제34권3호
• /
• pp.202-208
• /
• 2016

Purpose: Our institution has implemented two different adjuvant protocols in treating patients with non-small cell lung cancer (NSCLC): chemotherapy followed by concurrent chemoradiotherapy (CT-CCRT) and sequential postoperative radiotherapy (PORT) followed by postoperative chemotherapy (POCT). We aimed to compare the clinical outcomes between the two adjuvant protocols. Materials and Methods: From March 1997 to October 2012, 68 patients were treated with CT-CCRT (n = 25) and sequential PORT followed by POCT (RT-CT; n = 43). The CT-CCRT protocol consisted of 2 cycles of cisplatin-based POCT followed by PORT concurrently with 2 cycles of POCT. The RT-CT protocol consisted of PORT followed by 4 cycles of cisplatin-based POCT. PORT was administered using conventional fractionation with a dose of 50.4-60 Gy. We compared the outcomes between the two adjuvant protocols and analyzed the clinical factors affecting survivals. Results: Median follow-up time was 43.9 months (range, 3.2 to 74.0 months), and the 5-year overall survival (OS), locoregional recurrence-free survival (LRFS), and distant metastasis-free survival (DMFS) were 53.9%, 68.2%, and 51.0%, respectively. There were no significant differences in OS (p = 0.074), LRFS (p = 0.094), and DMFS (p = 0.490) between the two protocols. In multivariable analyses, adjuvant protocol remained as a significant prognostic factor for LRFS, favouring CT-CCRT (hazard ratio [HR] = 3.506, p = 0.046) over RT-CT, not for OS (HR = 0.647, p = 0.229). Conclusion: CT-CCRT protocol increased LRFS more than RT-CT protocol in patients with completely resected NSCLC, but not in OS. Further studies are warranted to evaluate the benefit of CCRT strategy compared with sequential strategy.

• 한국산학기술학회논문지
• /
• 제15권3호
• /
• pp.1584-1589
• /
• 2014

본 연구는 경기도 소재 S 대학병원에서 2013년 7월부터 8월까지 GE 사의 DECT(Dual Energy Computed Tomography)를 이용하여 방사선 투과 및 불투과성 물질을 임의로 선정, 에너지 영역 대별로 투과 및 불투과성 물질의 CT 값을 분석하였다. 또한, CT 값 분석 법을 이용하여 기존의 SECT(Single Energy Computed Tomography)에서 적용되는 120kVp CT 값과 가장 유사한 에너지 영역대를 도출하였으며 임상 적용 시 가시 영역 범위 내에서 대조도를 주었을 때 가장 유용하며 적절한 물질을 알아보았다. 결론으로 생리식염수, 메틸셀룰로스, 초음파용 젤과 같이 밀도가 낮고 수분 함유량이 많은 경우 90KeV 이후 CT 값의 감소가 거의 없었으며, 공기와 조영제처럼 밀도가 매우 낮거나 높은 물질의 경우 에너지의 영향을 적게 받는 것으로 분석되었으며 메틸셀룰로오스와 초음파 젤의 경우 임상 적용 시 가장 유용성이 있는 물질로 사료된다.

• 한국산학기술학회논문지
• /
• 제14권4호
• /
• pp.1871-1876
• /
• 2013

본 연구에서는 평균 입자의 크기가 $1{\sim}500{\mu}m$인 산화비스무스($Bi_2O_3$)와 평균 입자의 크기가 5 ~ 50 nm인 나노 황산바륨($BaSO_4$)을 사용하여 선량저감섬유(DRF; dose reduction fiber, (주)버팔로)를 개발하였다. 개발된 섬유를 시트 형태로 제작한 후 CT 검사시 발생한 산란선에 대한 차폐 특성을 조사하였다. 특성평가는 전리조와 인체 펜텀을 이용한 팬텀실험과 유리선량계를 이용한 임상실험을 병행하여 진행하였다. 임상실험에서는 3개 종합병원 60명의 환자에 대한 흉부 및 두부 CT 검사시 선량저감섬유를 사용하였을 때와 사용하지 않았을 때 안구, 흉부, 복부 및 생식선의 피부 및 심부 선량을 비교하여 차폐효과를 평가하였다. 본 연구를 통하여 개발된 선량저감섬유는 산란선에 의한 두부 및 흉부에 불필요한 피폭선량을 20~50% 정도 저감할 수 있는 것으로 확인되었으며, CT 검사시 본 섬유를 활용한다면 환자 피폭선량을 포함한 국민 총피폭선량 경감에 기여할 수 있을 것이다.

• 대한심미치과학회지
• /
• 제28권2호
• /
• pp.74-85
• /
• 2019

상악전치부에서 치아 임플란트의 심미적 회복은 경조직, 연조직, 심미적 보철물이 조화를 이루어야 하며 임상의에게 도전적인 과제이다. VIP-CT graft와 같은 새로운 기법이 많은 볼륨의 연조직 이식을 위해서 소개되어졌다. VIP-CT graft의 장점은 많은 연조직의 결손부위를 회복할 수 있고 술후 수축이 적다는 것이다. 게다가 그것은 부가적인 혈행공급을 통해 경조직의 증대도 촉진실킬 수 있다. 이 기법은 환자분의 불편감을 줄여주고 치료시간을 단축시킨다. 이 논문에서는 순면 결손부위가 있는 상악전치부에서 즉시 임플란트 식립을 할때 골이식과 VIP-CT graft 술식을 하는 과정에 대해 설명드리고자 한다.