• Korean Journal of Radiology
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• v.20 no.8
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• pp.1300-1310
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• 2019

Objective: To measure the diagnostic accuracy of percutaneous transthoracic needle lung biopsies (PTNBs) on the basis of the intention-to-diagnose principle and identify risk factors for diagnostic failure of PTNBs in a multi-institutional setting. Materials and Methods: A total of 9384 initial PTNBs performed in 9239 patients (mean patient age, 65 years [range, 20-99 years]) from January 2010 to December 2014 were included. The accuracy, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of PTNBs for diagnosis of malignancy were measured. The proportion of diagnostic failures was measured, and their risk factors were identified. Results: The overall accuracy, sensitivity, specificity, PPV, and NPV were 91.1% (95% confidence interval [CI], 90.6-91.7%), 92.5% (95% CI, 91.9-93.1%), 86.5% (95% CI, 85.0-87.9%), 99.2% (95% CI, 99.0-99.4%), and 84.3% (95% CI, 82.7-85.8%), respectively. The proportion of diagnostic failures was 8.9% (831 of 9384; 95% CI, 8.3-9.4%). The independent risk factors for diagnostic failures were lesions ≤ 1 cm in size (adjusted odds ratio [AOR], 1.86; 95% CI, 1.23-2.81), lesion size 1.1-2 cm (1.75; 1.45-2.11), subsolid lesions (1.81; 1.32-2.49), use of fine needle aspiration only (2.43; 1.80-3.28), final diagnosis of benign lesions (2.18; 1.84-2.58), and final diagnosis of lymphomas (10.66; 6.21-18.30). Use of cone-beam CT (AOR, 0.31; 95% CI, 0.13-0.75) and conventional CT-guidance (0.55; 0.32-0.94) reduced diagnostic failures. Conclusion: The accuracy of PTNB for diagnosis of malignancy was fairly high in our large-scale multi-institutional cohort. The identified risk factors for diagnostic failure may help reduce diagnostic failure and interpret the biopsy results.

• Radiation Oncology Journal
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• v.26 no.4
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• pp.271-279
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• 2008

Purpose: To evaluate the efficacy of a belly-board device (BBD) in reducing the volume of small bowel during four-field pelvic irradiation. Materials and Methods: Twenty-two cancer patients (14 uterine cervical cancer, 6 rectal cancer, and 2 endometrial cancer) scheduled to receive pelvic irradiation were selected for this study. Two sets of CT images were taken with and without the belly-board device using the Siemens 16 channel CT scanner. All patients were set in the prone position. The CT images were transferred to a treatment planning system for dose calculation and volume measurements. The external surfaces of small bowel and the bladder were contoured on all CT scans and the 4-pelvic fields were added. The dose-volume-histogram of the bladder and small bowel, with and without the BBD, were plotted and analyzed. Results: In all patients, the total small bowel volume included in the irradiated fields was reduced when the BBD was used. The mean volume reduction was 35% (range, $1{\sim}79%$) and was statistically significant (p<0.001). The reduction in small bowel volume receiving $10{\sim}100%$ of the prescribed dose was statistically significant when the BBD was used in all cases. Almost no change in the total bladder volume involved was observed in the field (<8 cc, p=0.762). However, the bladder volume receiving 90% of the prescribed dose was 100% in 15/22 patients (68%) and $90{\sim}99%$ in 7/22 patients (32%) with the BBD. In comparison, the bladder volume receiving 90% of the prescribed dose was 100% in 10/22 patients (45%), $90{\sim}99%$ in 7/22 patients (32%), and $80{\sim}89%$ in 5/22 patients (23%) without the BBD. When the BBD was used, an increase in the bladder volume receiving a high dose range was observed Conclusion: This study shows that the use of a BBD for the treatment of cancer in the pelvic area significantly improves small bowel sparing. However, since the BBD pushed the bladder into the treatment field, the bladder volume receiving the high dose could increase. Therefore it is recommended to be considerate in using the BBD when bladder damage is of concern.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.30 no.4
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• pp.292-300
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• 2004

Orbital blowout fractures are common consequence to blunt periorbital trauma. Pure orbital blowout fractures first occur at the weakest point of the orbital wall. Computed tomography(CT) is recognized to be the best imaging technique to evaluate orbital fractures. The extent and location of a blowout fractures in the CT scan were noted to have an effect on the clinical outcome. In the early posttraumatic period, the presence of significant enophthalmos is difficult to detect because of orbital edema. Early surgical intervention may improve the ultimate outcome because open reconstruction becomes more difficult if surgery is delayed. In this study, we evaluated isolated blowout fractures of the orbital floor by region-of-interest measurements from CT scans and their relationship to ophthalmologic findings. Six patients of the medial orbital wall fractures, eleven patients of the inferior orbital wall fractures, nineteen of the medial and the inferior orbital wall fractures confirmed by CT scan, were evaluated. The area of fracture and the volume of the displaced orbital tissue were determined from CT scan using linear measurements. Each of the calculated values for the area and the volume were compared with the degree of the enophthalmos, the diplopia, and the eyeball movement limitation to determine whether there was any significant relationship between them. The fracture area and the volume of the herniated orbital tissue were significantly positively correlated with the enophthalmos and the ocular motility limitation and not correlated with the diplopia. For the enophthalmos of 2mm or greater, the mean fracture area was 3.55{\pm}1.25cm^2$ and the volume of the herniated orbital tissue was $1.74{\pm}0.97cm^3$; for less than 2mm enophthalmos, $1.43{\pm}0.99cm^3$ and $0.52{\pm}0.49cm^3$, respectively. The enophthalmos of 2mm can be expected with $2.92cm^2$ of the fracture area and $1.40cm^3$ of the herniated orbital tissue. In conclusion, the enophthalmos of 2mm or more, which is a frequent indication for surgery. It can be expected when area of fracture is $2.92cm^2$ or more, or the volume of herniated orbital tissue is $1.40cm^3$ or more. And the CT scan using linear measurements has an application in the assessment of patients with blowout fractures and provides useful information in the posttraumatic evaluation of orbital fractures.

• Journal of Radiopharmaceuticals and Molecular Probes
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• v.5 no.1
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• pp.18-25
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• 2019

2-Nitroimidazole derivatives have been reported to accumulate in hypoxic tissue. We prepared a novel $^{99m}Tc-MAG_3$-2-nitroimidazole and evaluated the feasibility for hypoxia imaging agent. $Bz-MAG_3$-2-nitroimidazole was synthesized by direct coupling of $Bz-MAG_3$ and 2-nitroimidazole using dicyclohexylcarbodiimide. $Bz-MAG_3$-2-nitroimidazole was labeled with $^{99m}Tc$ in the presence of tartaric acid and $SnCl_2-2H_2O$ at $100^{\circ}C$ for 30 min. And the reaction mixture was purified by $C_{18}$ Sep-pak cartridge. The labeling efficiency and the radiochemical purity were checked by ITLC-SG/acetonitrile. The tumor was grown in balb/c mice for 8~13 days after the subcutaneous injection of tumor cells, CT-26 (murine colon adenocarcinoma cell). Biodistribution study and tumor autoradiography were performed in the xenografted mice after i.v injection of 74 kBq/0.1 mL and 19 MBq/0.1 mL of $^{99m}Tc-MAG_3$-2-nitroimidazole, respectively. In vivo images of $^{99m}Tc-MAG_3$-2-nitroimidazole in tumor bearing mice were obtained 1.5 hr post injection. The labeling efficiency was $45{\pm}20%$ and the radiochemical purity after purification was over 95%. Paper electrophoresis confirmed negative charge of $^{99m}Tc-MAG_3$-2-nitroimidazole. $^{99m}Tc-MAG_3$-2-nitroimidazole was very stable at room temperature and its protein binding was 53%. The $^{99m}Tc-MAG_3$-2-nitroimidazole exhibited high uptake in the liver, stomach and intestine. In biodistribution study using tumor bearing mice, the uptakes (% ID/g) of the tumor were $0.5{\pm}0.1$, $0.4{\pm}0.0$, $0.2{\pm}0.1$ and $0.1{\pm}0.1$ at 5, 15, 30 min and 4 hrs. Tumor/muscle ratio were $1.4{\pm}0.1$, $2.2{\pm}0.83$, $3.0{\pm}0.9$, and 3.7 (n=2) for 5, 15, 30 min and 4 hrs. The uptake in hypoxic area was found higher than in non-hypoxic area of tumor tissue by autoradiography. In vivo images showed the relatively faint uptake to the hypoxic tumor region. $^{99m}Tc-MAG_3$-2-nitroimidazole was successfully synthesized and found feasible for imaging hypoxia.

• The Korean Journal of Nuclear Medicine Technology
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• v.16 no.1
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• pp.17-26
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• 2012

Purpose: This study mainly focuses on the patients treated with chemically stable radiopharmaceutical product $^{99m}Tc$-HMPAO (d,l-hexamethylpropylene amine oxime) which yielded reduced image quality due to a decreased brain extraction rate. $^{99m}Tc$-HMPAO will be examined further to determine whether this product may be accounted as a factor for this cause. Material and Methods: From January 2010 until December 2010, out of 272 patients who were all subjected to $^{99m}Tc$-HMPAO brain blood flow SPECT scans resulting from Cerebral Infarction; 23 patients(ages $55.3{\pm}9$, 21 males, 3 females) with decreased tissue extraction rate were examined in detail. The radiopharmaceutical product $^{99m}Tc$-HMPAO was used on patients with normal brain tissue exchange rate as well as those with reduced rate in order to prove its' chemical stability. The patients' age, sex, blood pressure, existence of diabetes, drug use, current health status, known side effects from CT/MRI, examination of the patients' past SPECT before/after images were accounted to determine the factors and correlations affecting the rate of blood tissue extractions. Result: After multiple linear regression analysis, there were no unusual correlations between the 6 factors excluding sex, and before/after examination images. Male subjects showed reduced brain tissue extraction rate than the females ($p$ > 0.05) 91.3% male, 8.7% female. Wilcoxon Matched-Pairs Signed-Ranks Test was used on the before/after images which yielded a value of 0.06, which did not indicate a significant amount of difference on the 2 tests ($p$ > 0.05). As a result, the before/after images indicated similar brain tissue extraction rates, and there were variations depending on the individual patient. Conclusion: The effects of the chemically stable radiopharmaceutical product $^{99m}Tc$-HMPAO depended on the patient's personal characteristics and status, therefore was considered to be a factor in reducing brain tissue extraction rate. The related articles of $^{99m}Tc$-HMPAO cerebral blood flow SPECT speculates a cerebrovascular disease and factors resulting from portal veins, and it was not possible to pin point the exact cause of decreasing brain tissue extraction rate. However, the $^{99m}Tc$-HMPAO cerebral blood flow SPECT scan proved to be extremely useful in tracking and inspecting brain diseases, as well as offering accurate results from patients suffering from reduced brain tissue extraction rates.

• Korean Journal of Head & Neck Oncology
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• v.12 no.2
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• pp.235-240
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• 1996

Brain metastasis is extremely rare in thyroid papillary carcinoma which has an indolent clinical course and results in good prognosis. A 24-year-old man presenting with seizure attack is described. He had been treated under the diagnosis of thyroid papillary carcinoma with total thyroidectomy, postoperative internal radiation with radioactive iodine, and thyroid hormone replacement. Although $^{99m}$Tc brain spect and $^{131}$I whole body scan did not revealed any significant lesion, brain CT and MRI showed lcm sized mass in frontal lobe. Stereotactic craniotomy and removal of the tumor, which was histologically proven metastatic lesion from thyroid papillary carcinoma, was done with satisfactory improvement.

• Journal of radiological science and technology
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• v.42 no.6
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• pp.441-446
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• 2019

The purpose of this paper is to recognize the usefulness of the Phantom produced with 3D printing technology by reproducing the original phantom with 3D printing technology. Using CT, we obtained information from the original phantom. The acquired file was printed by the SLA method of ABS materials. For inspection, SPECT/CT was used to obtain images. We filled the both Phantom with a solution mixed with ^99mTcO4 1 mCi in 1 liter of water and acq uired images in accordance with the standard protocol. Using Image J, the SNR for each slice of the image was obtained. As a reference images, AC images were used. For the analysis of acquired images, ROI was set in the White mater and Gray mater sections of each image, and the average Intensity Value within the ROI were compared. According to the results of this study, 3D printed phantom's SNR is about 0.1 higher than the conventional phantom. And the ratio of Intensity Value was shown in the original 1 : 3.4, and the printed phantom was shown to be 1 : 3.2. Therefore, if Calibration Value is applied, It is assumed that it can be used as an alternative to the original.

• Korean Journal of Veterinary Research
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• v.60 no.3
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• pp.145-153
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• 2020

This study aimed to evaluate the effects of a bioabsorbable bone hemostatic agent comprising poly (ethylene glycol-propylene glycol) copolymers (PEG-PPG) on hemostasis and osteogenesis. Bilateral 3 mm diameter calvarial defects were created in 99 male Sprague-Dawley rats. The defects were filled with PEG-PPG or bone wax. The defects of control group were left unfilled. Virtual autopsy was performed to evaluate bioabsorption. The calvaria were subjected to x-ray microtomography (microCT) and histological examination. Bone volume fraction (BV/TV) and bone mineral density (BMD) were measured using microCT; furthermore, white blood cell count and histological examination were performed. After application of PEG-PPG and bone wax, immediate hemostasis was achieved. Autopsy revealed that PEG-PPG disappeared within 48 h at the application site; in contrast, bone wax remained until 12 weeks. The PEG-PPG and control groups showed significantly more osteogenesis than the bone wax group with respect to BV/TV and BMD at 3, 6, and 12 weeks (p < 0.05). Histology revealed that the bone wax group exhibited little bone formation with inflammation. In contrast, PEG-PPG and control groups showed significantly more qualitative osteogenesis than the bone wax group (p < 0.01). In conclusion, PEG-PPG showed immediate hemostasis and was absorbed to allow progressive osteogenesis.

• Tuberculosis and Respiratory Diseases
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• v.87 no.2
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• pp.134-144
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• 2024

Interstitial lung abnormalities (ILAs) are radiologic abnormalities found incidentally on chest computed tomography (CT) that can be show a wide range of diseases, from subclinical lung fibrosis to early pulmonary fibrosis including definitive usual interstitial pneumonia. To clear up confusion about ILA, the Fleischner society published a position paper on the definition, clinical symptoms, increased mortality, radiologic progression, and management of ILAs based on several Western cohorts and articles. Recently, studies on long-term outcome, risk factors, and quantification of ILA to address the confusion have been published in Asia. The incidence of ILA was 7% to 10% for Westerners, while the prevalence of ILA was about 4% for Asians. ILA is closely related to various respiratory symptoms or increased rate of treatment-related complication in lung cancer. There is little difference between Westerners and Asians regarding the clinical importance of ILA. Although the role of quantitative CT as a screening tool for ILA requires further validation and standardized imaging protocols, using a threshold of 5% in at least one zone demonstrated 67.6% sensitivity, 93.3% specificity, and 90.5% accuracy, and a 1.8% area threshold showed 100% sensitivity and 99% specificity in South Korea. Based on the position paper released by the Fleischner society, I would like to report how much ILA occurs in the Asian population, what the prognosis is, and review what management strategies should be pursued in the future.

• Journal of Korean Neurosurgical Society
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• v.29 no.5
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• pp.628-634
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• 2000

Objective : The introduction of MRI makes it easy to detect multiple lumbar disc herniation. However, MRI is not a physiologic test for detecting the symptomatic level. For the surgical plan, it is very important to determine the symtomatic level among the multiple lumbar disc herniation. In this regard, we studied diagnostic significance of discography on multiple lumbar disc herniation in determining the symptomatic level. Method and Material : We retrospectvely analyzed the discographic and clinical findings of 121 patients with multiple lumbar disc herniation for investigating the diagnostic availability of discography. All were surgically treated from January 1995 through May 1998. Result : Discography provocated the same pain as usual symptom in 99 out of 121 patients(81.8%). Compared with surgical findings, the diagnostic accuracy of the discography in multiple lumbar disc herniation was 75.6%, sensitivity was 64.6%, and specificity 87.2%. There was no correlation between the pain provocation of discography and the extent of annular degeneration on CT/discogram. The pain provocation showed good correlation with the extent of annular disruption on CT/discogram. The rate of same result(correlation rate) between the discography and D.I.T.I was 81.4% in multiple lumbar disc herniation patients with unilateral leg pain. Conclusion : These results indicate that in multiple lumbar disc herniation, the discography is considered useful diagnostic tool to determine the symptomatic level and to decide the surgical plan.