• 제목/요약/키워드: CT Coefficient

검색결과 214건 처리시간 0.029초

AN EXPLORATORY STUDY COMPARING BLOOD METAL CONCENTRATIONS BETWEEN STROKE AND NON-STROKE PATIENTS IN KOREANS

  • Lee, Sun-Dong;Ko, Seong-Gyu;Kim, Rok-Ho;Hu, Howard;Amarasiriwardena, Chitra J.;Park, Hae-Mo
    • 한국환경보건학회:학술대회논문집
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    • 한국환경보건학회 2005년도 Proceedings of KSEH.Minamata Forum
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    • pp.87-94
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    • 2005
  • Results from previous studies revealed that metal level in the body is related to certain types of diseases. For example. serum copper level with chronic heart failure, iron and transferrin in the blood serum with acute cerebral vascular diseases, Zn in the CNS, lead with neurotoxicity, hypertension, genetic damage, arsenic with cancer skin lesion, Al with neurobehavioral function (cognitive impairment and memory disorder), and etc. The rate of stroke has increased in recent years and several metals were found to be responsible for causing stroke. This study compared several blood metal concentrations between stroke and non-stroke patients. Patients with stroke (116 samples) and non-stroke (111 samples including lowback pain and others) participated in this study. Total of 227 blood samples were collected and participants completed questionnaires regarding age, gender, occupation, residence, alcohol, smoking, and etc. To be qualified into the stroke group, patients have never experienced stroke previously. Subjects only included ischemic stroke and intracerebral hemorrhage patients diagnosed by brain CT and brain MRI. Patients with high risk of metal exposure such as herbal intake and job related exposure were excluded. 10ml of blood samples were analyzed by ICP-MS method at the Center of Nature and Science at Sangji University. Metal geometric mean (SD) concentrations in blood of study subjects showed higher values, 2.64-36.12%, than WHO reference values in Mn, Ni, Hg, Se, and As. Metal concentration in blood of stroke patients non-adjusted for potential confounders was higher except for Hg and also higher except for Ni in adjusted for potential confounders. Co was significantly higher in stroke patients (p=0.002) than non-stroke patients adjusted for potential confounders. Regression coefficient values of stroke patients was 0.17-8.25 in each metals. Odd ratio of stroke patients had 0.96 (Ni)-2.68 (Co) compared to non-stroke cases. This result means that Co increase of 1 raises the risk ratio of stroke by 2.86 times. Based on the results, metal concentration in blood seems to affect incidence of stroke.

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Morphologic change of rectosigmoid colon using belly board and distended bladder protocol

  • Cho, Yeona;Chang, Jee Suk;Kim, Mi Sun;Lee, Jaehwan;Byun, Hwakyung;Kim, Nalee;Park, Sang Joon;Keum, Ki Chnag;Koom, Woong Sub
    • Radiation Oncology Journal
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    • 제33권2호
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    • pp.134-141
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    • 2015
  • Purpose: This study investigates morphologic change of the rectosigmoid colon using a belly board in prone position and distended bladder in patients with rectal cancer. We evaluate the possibility of excluding the proximal margin of anastomosis from the radiation field by straightening the rectosigmoid colon. Materials and Methods: Nineteen patients who received preoperative radiotherapy between 2006 and 2009 underwent simulation in a prone position (group A). These patients were compared to 19 patients treated using a belly board in prone position and a distended bladder protocol (group B). Rectosigmoid colon in the pelvic cavity was delineated on planning computed tomography (CT) images. A total dose of 45 Gy was planned for the whole pelvic field with superior margin of the sacral promontory. The volume and redundancy of rectosigmoid colon was assessed. Results: Patients in group B had straighter rectosigmoid colons than those in group A (no redundancy; group A vs. group B, 10% vs. 42%; p = 0.03). The volume of rectosigmoid colon in the radiation field was significantly larger in group A (56.7 vs. 49.1 mL; p = 0.009). In dose volume histogram analysis, the mean irradiated volume was lower in patients in group B (V45 27.2 vs. 18.2 mL; p = 0.004). In Pearson correlation coefficient analysis, the in-field volume of rectosigmoid colon was significantly correlated with the bladder volume (R = 0.86, p = 0.003). Conclusion: Use of a belly board and distended bladder protocol could contribute to exclusion of the proximal margin of anastomosis from the radiation field.

중증외상환자의 전산화단층촬영 및 중재술에 의한 방사선 유효선량 및 생애 귀속위험도 (Effective Radiologic Doses and Lifetime Attributable Risks in Patients with Trauma Critical Pathway Activation)

  • 이원효;공태영;김승환;유제성;박유석;이재길;정성필
    • Journal of Trauma and Injury
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    • 제26권3호
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    • pp.198-206
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    • 2013
  • Purpose: This study was performed to calculate and analyze the effective radiation doses from computed tomography (CT) and radiologic intervention in patients in the emergency department (ED) with trauma critical pathway (CP) activation and further to estimate the lifetime attributable risks (LARs) for the incidence of and mortality from cancers induced by the radiation dose. Methods: Through a retrospective electrical chart review of 104 injured patients who trauma critical pathway were activated from November 2012 to March 2013, we calculated effective radiologic doses by taking the product of the dose-linear product of the scan and the conversion coefficient. After a determination of the image results, we divided the patients into two groups, negative or positive, and calculated the effective dose for each group. With these results, we estimated the LARs for the incidence of and the mortality from cancers by using the table in the Biologic Effects of Ionizing Radiation (BEIR)-VII report. Results: A total of 76 patients were enrolled. The mean age was $49.0{\pm}8.5$ years. The mean injury severity score (ISS) was $12.7{\pm}8.4$. The cumulative effective dose (CED) for individual patients varied from 2.8 mSv to 238.8 mSv, and the mean was $47.6{\pm}39.9$ mSv. The CED in patients with an $ISS{\geq}16$($63.2{\pm}26.6$ mSv) was higher than that of patients whose ISS<16($33.5{\pm}23.1$ mSv) (p<0.001). The CED in patients who were treated with surgery or intervention($69.0{\pm}45.2$ mSv) was higher than that of patients who were treated conservatively($33.6{\pm}22.4$ mSv) (p<0.001). The LARs for cancer incidence and mortality were $328.5{\pm}308.6$ and $189.0{\pm}159.3$ per 100,000 people, respectively. Conclusion: The CED and the LAR for trauma CP-activated patients in the ED were significant, so efforts should be made to decrease the effective dose received by severely injured patients.

열 펌프의 식품 농축에의 이용 연구 (The Heat Pump Application to the Food Concentration)

  • 박노현;김병삼;강통삼;신동화
    • 한국식품과학회지
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    • 제19권6호
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    • pp.486-491
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    • 1987
  • 고효율의 열발생장치인 열펌프중, 국내에서 이용중인 압축식 열펌프에 대해 성능시험 및 식품농축분야에 이용코자 실증시험을 하였다. 국내에서 $43^{\circ}C$의 온천수를 $51^{\circ}C$까지 가열하기 위해 설치, 운전중인 냉매압축식열펌프(프레온12, 150HP)의 성적계수는 가열측이 4.03, 냉각측이 3.5로 나타났으며, 압축기 효율(${\alpha}$)은 0.477이었다. 또, 압축식열펌프를 국산화하기 위해 개발된 10HP의 열펌프(프레온22)에서 시수를 $39^{\circ}C$까지 가열하는 경우의 성적계수는 가열측이 3.0, 냉각측이 1.87이었다. 원심식농축기(${\alpha}$-LAVAL, CT1B)에 열펌프를 부착한후 설탕물의 농축실험을 한 결과, 수증기 응축에 소비된 열량이 농축에 필요한 증발잠열보다 15%정도 많이 소비되었고, 총괄열전달계수는 $1196\;Kcal/m^{2}{\cdot}h{\cdot}^{\circ}C$이었다. 또, 열펌프에서 제조되는 $60^{\circ}C$$15^{\circ}C$의 물을 열원으로 하여 마늘추출액을 저온농축(증발온도 : $30{\sim}35^{\circ}C$, 진공도 : $28{\sim}40$Torr)한 결과 농축에 소비된 열량과 수증기 응축열량과의 비는 0.961로 나타나 열펌프의 냉매 응축열과 증발열이 열수지 조절이 용이한 조건이었다. 따라서, 열펌프의 식품농축 분야에의 적용성은 매우 좋은 것으로 나타났다.

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The Ratio of Descending Aortic Enhancement to Main Pulmonary Artery Enhancement Measured on Pulmonary CT Angiography as a Finding to Predict Poor Outcome in Patients with Massive or Submassive Pulmonary Embolism

  • Park, Chi-Young;Yoo, Seung-Min;Rho, Ji-Young;Ji, Young-Geon;Lee, Hwa-Yeon
    • Tuberculosis and Respiratory Diseases
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    • 제72권4호
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    • pp.352-359
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    • 2012
  • Background: The purpose of this study was to evaluate whether measuring the ratio of descending aortic enhancement (DAE) to main pulmonary artery enhancement (MPAE) on pulmonary computed tomography angiography (PCTA) can predict poor outcome in patients with acute massive or submassive pulmonary embolism (PE). Methods: We retrospectively, reviewed computed tomgraphy findings and charts of 37 patients with acute PE and right ventricular dysfunction. We divided the enrolled patients into 3 groups; group Ia (n=8), comprised of patients with major adverse event (MAE); group Ib (n=5), consisted of those with PE-related MAE; and group II (n=29), those without MAE. We analyzed the right ventricular diameter (RVD)/left ventricular diameter (LVD) and DAE/MPAE on PCTA. Results: For observer 1, RVD/LVD in group Ia ($1.9{\pm}0.36$ vs. $1.44{\pm}0.38$, p=0.009) and group Ib ($1.87{\pm}0.37$ vs. $1.44{\pm}0.38$, p=0.044) were significantly higher than that of group II. For observer 2, RVD/LVD in group Ia ($1.71{\pm}0.18$ vs. $1.41{\pm}0.47$, p=0.027) was significantly greater than that of group II, but RVD/LVD of group Ib was not ($1.68{\pm}0.2$ vs. $1.41{\pm}0.47$, p=0.093). For both observers, there was a significant difference of DAE/MPAE between group Ib and group II ($0.32{\pm}0.15$ vs. $0.64{\pm}0.24$, p=0.005; $0.34{\pm}0.16$ vs. $0.64{\pm}0.22$, p=0.004), but no significant difference of DAE/MPAE between group Ia and group II ($0.51{\pm}0.3$ vs. $0.64{\pm}0.24$, p=0.268; $0.53{\pm}0.29$ vs. $0.64{\pm}0.22$, p=0.302). Intra-class correlation coefficient (ICC) for the measurement of DAE/MPAE (ICC=0.97) was higher than that of RVD/LVD (ICC=0.74). Conclusion: DAE/MPAE measured on PCTA may predict PE-related poor outcomes in patients with massive or submassive PE with an excellent inter-observer agreement.

강자성공명을 이용한 $Co_{84}\;Hf_{16}$ 박막의 자기적 성질 연구 (The Magnetic Properties of $Co_{84}\;Hf_{16}$ Thin Films by FMR)

  • 김기현;장재호;김영호
    • 한국자기학회지
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    • 제7권4호
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    • pp.191-195
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    • 1997
  • DC magnetron sputtering 방법에 의해 $Co_{84}$H $f_{16}$ 박막 (1300 .angs. , 2150 .angs. )을 제작하였다. 박막의 자기적 특성을 조사하기 위해서 J-band (7.42 GHz) 마이크로파 영역의 강자성 공명 (ferromagnetic resonance) 장치를 이용하였다. 측정된 공명 흡수선의 주 모드(main mode)로부터 계산된 분광학적 분리상수 g 값은 1300 .angs. , 2150 .angs. 일 때 각각 2.06과 2.07이었으며, 상온에서의 유효 자화(4 .pi. $M_{eff}$)값은 10385 emu/$cm^{3}$,10770 emu/$cm^{3}$였다. 자기 이방성을 조사하기 위해 VSM(vibrating sample magnetometer)을 이용하여 측정된 포화자화(4 .pi. $M_{s}$ )값은 16409 emu/$cm^{3}$와 14222 emu/$cm^{3}$였다. 유효 이방성 자기장 $H_{A}$ (effective anisotropy field)과 일축 이방성상수 $K_{u}$ (uniaxial anisotropy constant)는 각각 6024 Oe, 3452 Oe와 3.93 * $10^{6}$ erg/$cm^{3}$, 1.95 * $10^{6}$erg/$cm^{3}$였다. 77K에서 상온까지 온도에 따른 유효 포화 자화(4 .pi. $M_{eff}$)값을 측정하였으며, 포화자화의 온도의존성은 Bloch 법칙을 잘 만족시켰다. 이 포화자화곡선을 최적화하여 Bloch 상수 B, C를 구하였고, 77K에서 0K까지 외삽법으로 구한 $M_{eff}$(0)는 각각 894 erg/$cm^{3}$, 891 erg/$cm^{3}$였으며, 스핀파 경도 상수 D값과 교환 경도 상수 $A_{eff}$는 각각 148 meV .angs. $^{2}$, 103.8 meV .angs. $^{2}$와 1.77 * $10^{-6}$ erg/cm, 0.67 * $10^{-6}$ erg/cm 였다.다.

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Clinical and Radiological Features of Diffuse Lacrimal Gland Enlargement: Comparisons among Various Etiologies in 91 Biopsy-Confirmed Patients

  • Sae Rom Chung;Gye Jung Kim;Young Jun Choi;Kyung-Ja Cho;Chong Hyun Suh;Soo Chin Kim;Jung Hwan Baek;Jeong Hyun Lee;Min Kyu Yang;Ho-Seok Sa
    • Korean Journal of Radiology
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    • 제23권10호
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    • pp.976-985
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    • 2022
  • Objective: To compare the clinical and radiological features of various etiologies of chronic diffuse lacrimal gland enlargement. Materials and Methods: We retrospectively reviewed 91 consecutive patients who underwent surgical biopsy for chronic diffuse lacrimal gland enlargement and were diagnosed with non-specific dacryoadenitis (DA) (n = 42), immunoglobulin G4-related dacryoadenitis (IgG4-RD) (n = 33), and lymphoma (n = 16). Data on patient demographics, clinical presentation, and CT imaging findings (n = 73) and MRI (n = 43) were collected. The following radiologic features of lacrimal gland enlargement were evaluated: size, unilaterality, wedge sign, angle with the orbital wall, heterogeneity, signal intensity, degree of enhancement, patterns of dynamic contrast-enhanced, and apparent diffusion coefficient value. Radiological features outside the lacrimal glands, such as extra-lacrimal orbital involvement and extra-orbital head and neck involvement, were also evaluated. The clinical and radiological findings were compared among the three diseases. Results: Compared to the DA and IgG4-RD groups, the lymphoma group was significantly older (mean 59.9 vs. 46.0 and 49.4 years, respectively; p = 0.001) and had a higher frequency of unilateral involvement (62.5% vs. 31.0% and 15.2%, respectively; p = 0.004). Compared to the IgG4-RD and lymphoma groups, the DA group had significantly smaller lacrimal glands (2.3 vs. 2.8 and 3.3 cm, respectively; p < 0.001) and a lower proportion of cases with a wedge sign (54.8% vs. 84.8% and 87.5%, respectively; p = 0.005). The IgG4-RD group showed more frequent involvement of the extra-orbital head and neck structures, including the infraorbital nerve (36.4%), paranasal sinus (72.7%), and salivary gland (58.6%) compared to the DA and lymphoma groups (4.8%-28.6%) (all p < 0.005). Conclusion: Patient age, unilaterality, lacrimal gland size, wedge sign, and extra-orbital head and neck involvement differed significantly different between lymphoma, DA, and IgG4-RD. Our results will be useful for the differential diagnosis and proper management of chronic lacrimal gland enlargement.

Is the Mixed Use of Magnetic Resonance Enterography and Computed Tomography Enterography Adequate for Routine Periodic Follow-Up of Bowel Inflammation in Patients with Crohn's Disease?

  • Jiyeon Ha;Seong Ho Park;Jung Hee Son;Ji Hun Kang;Byong Duk Ye;So Hyun Park;Bohyun Kim;Sang Hyun Choi;Sang Hyoung Park;Suk-Kyun Yang
    • Korean Journal of Radiology
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    • 제23권1호
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    • pp.30-41
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    • 2022
  • Objective: Computed tomography enterography (CTE) and magnetic resonance enterography (MRE) are considered substitutes for each other for evaluating Crohn's disease (CD). However, the adequacy of mixing them for routine periodic follow-up for CD has not been established. This study aimed to compare MRE alone with the mixed use of CTE and MRE for the periodic follow-up of small bowel inflammation in patients with CD. Materials and Methods: We retrospectively compared two non-randomized groups, each comprising 96 patients with CD. One group underwent CTE and MRE (MRE followed by CTE or vice versa) for the follow-up of CD (interval, 13-27 months [median, 22 months]), and the other group underwent MRE alone (interval, 15-26 months [median, 21 months]). However, these two groups were similar in clinical characteristics. Three independent readers from three different institutions determined whether inflammation had decreased, remained unchanged, or increased within the entire small bowel and the terminal ileum based on sequential enterography of the patients after appropriate blinding. We compared the two groups for inter-reader agreement and accuracy (terminal ileum only) using endoscopy as the reference standard for enterographic interpretation. Results: The inter-reader agreement was greater in the MRE alone group for the entire small bowel (intraclass correlation coefficient [ICC]: 0.683 vs. 0.473; p = 0.005) and the terminal ileum (ICC: 0.656 vs. 0.490; p = 0.030). The interpretation accuracy was higher in the MRE alone group without statistical significance (70.9%-74.5% vs. 57.9%-64.9% in individual readers; adjusted odds ratio = 3.21; p = 0.077). Conclusion: The mixed use of CTE and MRE was inferior to MRE alone in terms of inter-reader reliability and could probably be less accurate than MRE alone for routine monitoring of small bowel inflammation in patients with CD. Therefore, the consistent use of MRE is favored for this purpose.

DMIDR 장치의 재구성 알고리즘 별 성능 평가 (Performance Evaluation of Reconstruction Algorithms for DMIDR)

  • 곽인석;이혁;문승철
    • 핵의학기술
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    • 제23권2호
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    • pp.29-37
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    • 2019
  • DMIDR (General Electric Healthcare, USA)은 GE 사(社)의 최신 장비로써 PSF (Point Spread Function reconstruction), TOF(Time of Flight)와 Q.Clear의 적용이 가능하다. 특히, Q.Clear는 보정 알고리즘으로써 복셀(voxel)단위 신호 잡음 제거로 기존 OSEM (Ordered Subset Expectation Maximization)의 한계를 넘어설 수 있다. 따라서 이러한 재구성 및 보정 알고리즘의 성능 평가를 통해 정확한 SUV를 구현하며, 병변 검출 능력에 도움이 되는 알고리즘의 조합을 확인하고자 하였다. H/B(Hot & Background) Ratio 2:1, 4:1, 8:1의 비율로 NEMA/IEC 2008 PET phantom을 제작하였다. DMIDR의 NEMA test protocol을 이용하여 영상 획득을 하였다. 재구성 조합은 (1) VPFX(VUE point FX(TOF)), (2) VPHD-S(VUE point HD+PSF), (3) VPFX-S(TOF+PSF), (4) QCHD-S-400(VUE point HD+Q.Clear(${\beta}-strength$ 400)+PSF), (5) QCFX-S-400(TOF+Q.Clear(${\beta}-strength$ 400)+PSF), (6) QCHD-S-50(VUE point HD+Q.Clear(${\beta}-strength$ 50)+PSF), (7) QCFX-S-50(TOF+Q.Clear(${\beta}-strength$ 50) + PSF)의 7 가지로 구성하였다. H/B Ratio 및 재구성 알고리즘 별로 측정된 결과를 이용하여 CR (Contrast Recovery)와 BV (Background Variability)을 구하였다. 또한, 각 조합의 count를 측정하여 SNR (Signal to Noise Ratio)과 RC(Recovery Coefficient)를 구하고 SUV (Standardized Uptake Value)를 측정하였다. 구의 크기가 가장 작은 10 mm와 13 mm에서는 VPFX-S, 17 mm 이상에서는 QCFX-S-50에서 가장 높은 CR 결과를 보였다. BV와 SNR의 비교에서는 QCFX-S-400과 QCHD-S-400에서 좋은 값을 보였다. SUV 측정 결과는 H/B ratio와 비례하여 증감하는 양상을 보였다. SUV에 대한 RC의 경우 H/B ratio와 반비례하는 양상을 보였으며, 재구성 알고리즘 중에서는 QCFX-S-50이 가장 높은 값을 보였다. 또한, Q.Clear에 ${\beta}-strength$ 400이 적용된 재구성 알고리즘들이 낮은 값 분포를 보였다. Q.Clear가 적용된 재구성 조합은 ${\beta}-strength$를 높이면 신호잡음이 억제되어 영상 품질면에서 우수한 결과를 보였고 ${\beta}-strength$를 낮추면 선예도가 증가하며, partial volume effect가 감소하여 기존의 재구성 조건에 비하여 높은 RC에 근거한 SUV 측정이 가능하였다. 이러한 진보된 알고리즘의 사용으로 보다 정확한 정량화와 미세병변 검출능력을 향상 시킬 수 있으나 상관 관계를 고려하여 목적에 맞는 최적화 과정이 필요할 것으로 사료된다.

장수허리노린재(Anoplocnemis dallasi Kiritschenko)의 成長分析 (An Analytical Study on the Growth of Anoplocnemis dallasi Kiritschenko)

  • 박상옥;이창언
    • 한국동물학회지
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    • 제14권3호
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    • pp.139-158
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    • 1971
  • 장수허리노린재(Anoplocnemis dallasi Kiritschenko)의 第1齡 幼蟲(50個體)부터 成蟲까지(各 70個體씩)에서 얻은 實測値를 定式化하여 成長 및 相對成長을 分析 觀察한 結果 다음과 같은 結論을 얻었다. $\circled1$ 成長量 : 口吻이 가장 緩慢한 直線狀 增加를 하고 그 外는 모두 急激한 抛物線狀 增加를 나타내며 體長, 後脚, 中脚, 前脚, 觸角, 前胸背板의 幅, 口吻의 順으로 體長이 가장 急激하게 增加한다. $\circled2$ 成長比 : 口吻의 增加率 3.054倍가 가장 적으며 直線狀 增加를 나타내고 그 外는 모두 抛物線狀 增加를 보이며 前胸背板의 幅의 增加率 8.186倍가 가장 크다. $\circled3$ 各 齡別成長比 : 가장 큰 成長比는 若齡 幼蟲쪽에 있으며 가장 적은 成長比는 老齡 幼蟲쪽에 있다. $\circled4$ 成長率 : 觸角의 그것이 減少되었으며 그 外는 모두 增加되었다. $\circled5$ 比成長率 : 觸角이 가장 急하게 減少되었으며 前脚, 口吻, 後脚, 中脚의 順으로 緩慢해졌고 前胸背板의 幅과 體長은 上昇되다가 減少되었다. $\circled6$ 相對成長係數($\alpha$)는 위의 모든 部位에 對해서 前胸背板의 幅의 그것이 항상 가장 强한 優成長이었고 口吻은 가장 弱한 劣成長이었다. $\circled7$ 對 體長, 對前胸背板의 幅, 對觸角, 對口吻, 對前脚, 對中脚, 對後脚 相對成長에서 各 部分의 相對成長係數($\alpha$)는 同一한 樣式(順序)을 나타낸다. $\circled8$ 相對成長係數 $\alpha$가 增加하면 相對成長 初量 b가 減少하는 傾向을 나타내며 그 逆도 成立한다. $\circled9$ 劣成長일 境遇는 成長中心이 若齡基에 있고 優成長일 境遇는 老齡基에 있다.

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