• Journal of Yeungnam Medical Science
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• v.30 no.2
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• pp.116-119
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• 2013

A burnt-out prostate cancer tumor is a very rare clinical entity. The term 'burnt-out' refers to a primary tumor that has spontaneously and nearly completely regressed without treatment. Since metastasis of prostate cancer is usually encountered in the presence of advanced disease, distant metastasis with an undetectable primary tumor is very rare. We report herein a case of a burnt-out prostate cancer tumor that metastasized to the thoracic (T) spine and caused cord compression. A 66-year-old man visited the Emergency Department due to weakness of both legs for the past two days. His blood and urine tests were normal at the time. His spine magnetic resonance imaging (MRI) scans looked like bone metastasis that involved the T-7 vertebral body and a posterior element, and caused spinal cord compression. Other images, including from the brain MRI, neck/chest/abdomino-pelvic computed tomography (CT) scan and 18F-fluorodeoxyglucose (FDG)-positron emission tomography (PET) and endoscopy, revealed no lesions that suggested malignancy. After total corpectomy T-7 and screw fixation/fusion at T5 to T10, the pathology report revealed a metastatic carcinoma that was strongly positive for prostate-specific antigen (PSA). The serum PSA value was 1.5 ng/mL. The transrectal 12-core prostate biopsy and ultrasonography showed no definitive hypoechoic lesion, but one specimen had slight (only 1%) adenocarcinoma with a Gleason score of 6 (3+3). The final diagnosis was burned-out prostate cancer with an initial normal PSA value. Although metastatic disease with an unknown primary origin was confirmed, a more aggressive approach in seeking the primary origin could provide a more specific treatment strategy and greater clinical benefit to patients.

• Tuberculosis and Respiratory Diseases
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• v.61 no.6
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• pp.578-584
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• 2006

A primary choriocarcinoma of the lung is extremely rare, and difficult to distinguish from a metastatic choriocarcinoma considering that the lung is also one of the most frequent sites of metastasis. We report a 28-year-old woman patient who was initially misdiagnosed with an ectopic pregnancy and was operated on under the impression of an unidentified malignancy of the lung, which was finally proven to be a choriocarcinoma of the lung. A pelvic examination by a gynecologist, pelvic magnetic resonance imaging and whole body fluorodeoxyglucose positron emission tomography-computed tomography was performed in order to rule out a metastatic choriocarcinoma of the lung. After a curative operation, her serum ${\beta}$-human chorionic gonadotropin (HCG) level, which was highly elevated in the initial evaluation, had decreased dramatically to the normal range. She is currently being followed up regularly without any evidence of recurrence or elevation of her ${\beta}$-HCG level.

• Korean Journal of Radiology
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• v.22 no.3
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• pp.464-475
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• 2021

Objective: This study aimed to evaluate the tumor doubling time of invasive lung adenocarcinoma according to the International Association of the Study for Lung Cancer (IASLC)/American Thoracic Society (ATS)/European Respiratory Society (ERS) histologic classification. Materials and Methods: Among the 2905 patients with surgically resected lung adenocarcinoma, we retrospectively included 172 patients (mean age, 65.6 ± 9.0 years) who had paired thin-section non-contrast chest computed tomography (CT) scans at least 84 days apart with the same CT parameters, along with 10 patients with squamous cell carcinoma (mean age, 70.9 ± 7.4 years) for comparison. Three-dimensional semiautomatic segmentation of nodules was performed to calculate the volume doubling time (VDT), mass doubling time (MDT), and specific growth rate (SGR) of volume and mass. Multivariate linear regression, one-way analysis of variance, and receiver operating characteristic curve analyses were performed. Results: The median VDT and MDT of lung cancers were as follows: acinar, 603.2 and 639.5 days; lepidic, 1140.6 and 970.1 days; solid/micropapillary, 232.7 and 221.8 days; papillary, 599.0 and 624.3 days; invasive mucinous, 440.7 and 438.2 days; and squamous cell carcinoma, 149.1 and 146.1 days, respectively. The adjusted SGR of volume and mass of the solid-/micropapillary-predominant subtypes were significantly shorter than those of the acinar-, lepidic-, and papillary-predominant subtypes. The histologic subtype was independently associated with tumor doubling time. A VDT of 465.2 days and an MDT of 437.5 days yielded areas under the curve of 0.791 and 0.795, respectively, for distinguishing solid-/micropapillary-predominant subtypes from other subtypes of lung adenocarcinoma. Conclusion: The tumor doubling time of invasive lung adenocarcinoma differed according to the IASCL/ATS/ERS histologic classification.

• Journal of the Korean Society of Radiology
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• v.81 no.6
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• pp.1424-1435
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• 2020

Purpose The purpose of this study was to evaluate the usefulness of multiphasic CT and ¹⁸F-fluorodeoxyglucose (FDG) PET/CT for the differentiation of combined hepatocellular carcinoma-cholangiocarcinoma (cHCC-CCA) from hepatocellular carcinoma (HCC). Materials and Methods From January 2007 to April 2016, 93 patients with pathologically confirmed HCC (n = 84) or cHCC-CCA (n = 9) underwent CT and PET/CT imaging. Contrast enhancement patterns were divided into three types based on the attenuation of the surrounding liver parenchyma: type I (early arterial enhancement with delayed washout), type II (early arterial enhancement without delayed washout), and type III (early hypovascular, infiltrative appearance, or peripheral rim enhancement). Results cHCC-CCAs (89%) had a higher PET/CT positive rate than did HCCs (61%), but the PET/CT positive rate did not differ significantly (p = 0.095). Among the 19 cases of the type II enhancement pattern, 3 (21%) of 14 HCCs and 4 (80%) of 5 cHCC-CCAs were PET/CT positive. cHCC-CCAs had a significantly higher PET/CT positive rate (p = 0.020) in the type II enhancement pattern. Conclusion The PET/CT positive rate of cHCC-CCA was significantly higher than that of HCC in lesions with a type II enhancement pattern. The ¹⁸F-FDG PET/CT can be useful for the differentiation of cHCC-CCA from HCC in lesions with a type II enhancement pattern on multiphasic CT.

• Nuclear Medicine and Molecular Imaging
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• v.40 no.6
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• pp.309-315
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• 2006

Purpose: Accurate evaluation of cervical lymph node (LN) metastasis of head and neck squamous cell canter (SCC) is important to treatment planning. We evaluated the diagnostic accuracy of F-18 fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) for the detection of cervical LN metastasis of head and neck SCC and performed a retrospective comparison with CT/MRI findings. Materials & Methods: Seventeen patients with pathologically proven head and neck SCC underwent F-18 FDG PET/CT and CT/MRI within 4 week before surgery. We recorded lymph node metastases according to the neck level system of imaging-based nodal classification. F-18 FDG PET/CT images were analyzed visually for assessment of regional tracer uptake in LN. We analyzed the differences in sensitivity and specificity between F-18 FDG PET/CT and CT/MRI using the Chi-square test. Results: Among the 17 patients, a total of 123 LN levels were dissected, 29 of which showed metastatic involvement. The sensitivity and specificity of F-18 FDG PET/CT for detecting cervical LN metastasis on a level-by-level basis were 69% (20/29) and 99% (93/94). The sensitivity and specificity of CT/MRI were 62% (18/29) and 96% (90/94). There was no significant difference in diagnostic accuracy between F-18 FDG PET/CT and CT/MRI. Interestingly, F-18 FDG PET/CT detected double primary tumor (hepatocellular carcinoma) and rib metastasis, respectively. Conclusion: There was not statistically significant difference of diagnostic accuracy between F-18 FDG PET/CT and CT/MRI for the detection of cervical LN metastasis of head and neck SCC. The low sensitivity of F-18 FDG PET/CT was due to limited resolution for small metastatic deposits.

• The Journal of the Korean bone and joint tumor society
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• v.20 no.2
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• pp.66-73
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• 2014

Purpose: Various diagnostic imaging modalities have been used to evaluate the effect of neoadjuvant chemotherapy for osteosarcoma early and noninvasively. We evaluated the effectiveness of imaging studies of plain radiographs and positron-emission tomography/computed tomography (PET/CT) in predicting neoadjuvant chemotherapy effect for osteosarcoma and tried to establish a general principle in interpretation of PET/CT parameters. Materials and Methods: Eighteen patients who underwent two cycles of neoadjuvant chemotherapy and surgical excision for osteosarcoma were enrolled. There were 13 males and 5 females, with a median age of 19 (11-63) years. Fifteen patients of 18 had the American Joint Committe on Cancer (AJCC) stage IIB. They had plain radiographs and PET/CT before and after neoadjuvant chemotherapy. The resected tumor specimens were pathologically examined to determine histological response grade using a conventional mapping method. Statistical analysis was performed to evaluate the correlation between histopathological necrosis rate, and radiographic finding category, post-chemotherapy maximum standardized uptake value (SUVmax), average standardized uptake value and metabolic tumor volume (MTV) as well as reduction rates of them. Results: Eight patients were good responders to neoadjuvant chemotherapy based on histological evaluation. Median SUVmax reduction rate was 73 (23-77) % in good responders and 42 (-32-76) % in poor responders. Median MTV reduction rate was 93.5 (62-99) % in good responders and 46 (-81-100) % in poor responders. While radiographic finding category was not different according to histological response (p=1.0), SUVmax reduction rate was significantly different (p=0.041). Difference in MTV reduction rates approached statistical significance as well (p=0.071). Conclusion: While radiographic finding category was not reliable to assess neoadjuvant chemotherapy effect for osteosarcoma, reduction rate of SUVmax was a useful indicator in this study. As parameters of PET/CT can be influenced by various factors of settings, different centers have to make an effort to establish their own standard of judgement with reference of previous studies.

• Investigative Magnetic Resonance Imaging
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• v.13 no.2
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• pp.152-160
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• 2009

Purpose : To intra-individually compare diagnostic accuracy of high-resolution contrast-enhanced magnetic resonance angiography (CE-MRA) with computed tomography angiography (CTA) and digital subtraction angiography (DSA) for the assessment of supraaortic steno-occlusive disease. Materials and Methods : Twenty-eight patients (20 men, 8 women, 53-79 years of age) underwent supraaortic CE-MRA, CTA and DSA. CE-MRA was performed on two 1.5T MR scanners (voxel dimension: $0.66{\times}0.66{\times}1.1$ or $1.2\;mm^3$), and CTA on 64-slice CT scanners (voxel dimension: $0.42{\times}0.42{\times}0.63\;mm^3$). All the three examinations were completed within 40 days (median 19 days; range 1-40 days). Retrospective evaluation and measurement of diameter of 6 extracranial and 9 intracranial arterial segments was done by 2 experienced radiologists. Results: A total of 420 arterial segments were examined by CE-MRA, CTA and DSA. On DSA, 34 stenoocclusive lesions were noted at extracranial (n= 19) and intracranial (n = 15) vessels. For extracranial stenosis greater than 70%, sensitivity, specificity, positive predictive value (PPV) and negative predictive values (NPV) were 94.7%, 98.7%, 90.0% and 99.3% on CE-MRA, and 94.7%, 99.3%, 94.7% and 99.3% on CTA. For intracranial stenosis greater than 50%, sensitivity; specificity, PPV and NPV were 93.3%, 98.3%, 77.8%and 99.6% on CE-MRA, and 86.7%, 97.9%, 72.2% and 99.1 % on CTA, with DSA as the standard of reference. Conclusion : Supraaortic CE-MRA is as reliable as CTA in depicting the arterial stenosis, and is effective in screening of significant stenosis of both extracranial and intracranial arterial stenosis.

• Journal of Dental Rehabilitation and Applied Science
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• v.24 no.4
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• pp.389-403
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• 2008

In Angle's Class III malocclusion, which has higher incidence in Korean than Western, depressed midfacial profile with protruded lower lips and mandible may give rise to many functional, esthetic, psychological, social problems. Due to the different malocclusion incidence according to racial differences, many previous studies focused on the relationship between Class II malocclusion and nasal airway obstruction. Previous studies used lateral cephalography which has limitations of 2 dimensional image with projection error and identification error. Therefore, the purpose of this study was to analyze morphologic differences in the nasal airway between normal occlusion and Angle's Class III malocclusion patients using 3-dimensional facial computed tomography. Thirteen normal occlusion(7 men and 6 women) and sixteen skeletal Class III(7 men and 9 women) patients were selected and 3-dimensional facial computed tomography taking was performed. Comparison between two group in volume and sectional area of nasal airway were carried out. The results were followed. 1. In the comparison of absolute nasal airway volume, oropharyngeal space of experimental group were larger than control group but there are no significant difference in other. 2. In the comparison of relative nasal airway volume, oropharyngeal space of experimental group were larger than control group but there are no significant difference in other. 3. In the oropharyngeal space width on frontal and lateral view, the similar tendency was revealed between two groups. 4. In the lateral curvature of nasal airway, the similar tendency was revealed between two groups.

• 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.

• Progress in Medical Physics
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• v.19 no.3
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• pp.178-185
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• 2008

Living donor liver transplantation is increasingly performed as an alternative to cadaveric transplantation. Preoperative screening of the donor candidates is very important. The quality, size, and vascular and biliary anatomy of the liver are best assessed with magnetic resonance (MR) imaging or computed tomography (CT). In particular, the volume of the potential graft must be measured to ensure sufficient liver function after surgery. Preoperative liver segmentation has proved useful for measuring the graft volume before living donor liver transplantations in previous studies. In these studies, the liver segments were manually delineated on each image section. The delineated areas were multiplied by the section thickness to obtain volumes and summed to obtain the total volume of the liver segments. This process is tedious and time consuming. To compensate for this problem, automatic segmentation techniques have been proposed with multiplanar CT images. These methods involve the use of sequences of thresholding, morphologic operations (ie, mathematic operations, such as image dilation, erosion, opening, and closing, that are based on shape), and 3D region growing methods. These techniques are complex but require a few computation times. We made a phantom for volume measurement with pig and evaluated actual volume of spleen and liver of phantom. The results represent that our semiautomatic volume measurement algorithm shows a good accuracy and repeatability with actual volume of phantom and possibility for clinical use to assist physician as a measuring tool.