• Journal of Yeungnam Medical Science
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• v.16 no.2
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• pp.296-301
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• 1999

Background: Generally, it is difficult to differentiate uterine malignant mixed M$\ddot{u}$ llerian tumor(MMMT) from endometrial carcinom in radiological and clinical aspects. Our purpose is to investigate MR findings that distinguishes MMMT from endometrial carcinoma. Materials and Methods: We retrogradely evaluated the magnetic resonance imaging findings of pathologically proven 5 cases of malignant mixed M$\ddot{u}$llerian tumor(MMMT) and 14 endometrial carcinomas to know the differential points of these two tumors originating in the endometrial cavity. The size of the mass, presence or absence of myometrial or uterine cervical invasion, growth pattern of the mass, signal intensity and degree and pattern of contrast enhancement were analyzed and compared. Results: The length of the long axis of the MMMT was 1.5-9.0cm(average, 5.7cm) but that of the endometrial carcinoma was 0.5-6.0cm(average, 2.5cm). Invasion of uterine cervix which was found in 3 MMMT cases, dilated the endometrial cavity and the lumen of the uterine cervix and showed the pattern of growing into the external os. Invasion of uterine cervix was found in only one case of endometrial carcinoma. The presence or absence of myometrial invasion, the signal intensity and homogeneity on T1- and T2-weighted images, and the degree and patterns of contrast enhancement showed no significant difference. Conclusion: Any specific finding to differentiate MMMT from endometrial carcinoma was not ascertained. However, MMMT can be suspected if the size of the endometrial mass is greater than 5cm and if the mass dilates the enocervical canal and invades the uterine cervix.

• Investigative Magnetic Resonance Imaging
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• v.16 no.2
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• pp.189-194
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• 2012

We report a case of cardiac lymphoma in a 40-year-old man, who had a mediastinal mass which was diagnosed as sclerosing mediastinitis pathologically. The mediastinal mass caused right pulmonary arterial stenosis. The patient developed myocardial hypertrophy and echocardiography showed restrictive physiology and severely decreased left ventricle ejection fraction, 6 months later. MRI showed global left ventricular myocardial hypertrophy and diffuse late gadolinium hyperenhancement after administration of contrast material. Thus, non-ischemic cardiomyopathy was suspected on MRI. However, pathology confirmed the myocardial abnormality as lymphoma after myocardial biopsy. Because a basal part of the left ventricle and global subendocardial myocardium were not involved on contrast-enhanced delayed MRI, the MRI abnormalities could be differentiated from amyloidosis and other myocardial diseases. The peculiar non-mass forming diffuse hypertrophy pattern of cardiac lymphoma has not been known in the MRI literature.

• KIPS Transactions on Software and Data Engineering
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• v.1 no.2
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• pp.109-114
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• 2012

Honeycombs are dense structures that small cysts, which generally have about 2~10 mm in diameter, are surrounded by the wall of fibrosis. When honeycomb is found in the patients, the incidence of acute exacerbation is generally very high. Thus, the observation and quantitative measurement of honeycomb are considered as a significant marker for clinical diagnosis. In this point of view, we propose an automatic segmentation method using morphological image processing and assessment of the degree of clustering techniques. Firstly, image noises were removed by the Gaussian filtering and then a morphological dilation method was applied to segment lung regions. Secondly, honeycomb cyst candidates were detected through the 8-neighborhood pixel exploration, and then non-cyst regions were removed using the region growing method and wall pattern testing. Lastly, final honeycomb regions were segmented through the extraction of dense regions which are consisted of two or more cysts using cluster analysis. The proposed method applied to 80 High resolution computed tomography (HRCT) images and achieved a sensitivity of 89.4% and PPV (Positive Predictive Value) of 72.2%.

• Nuclear Medicine and Molecular Imaging
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• v.40 no.5
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• pp.249-256
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• 2006

Purpose: Although computed tomography (CT) is widely used for diagnosing liver metastasis from colorectal cancer, diagnostic accuracy of CT is not satisfactory. Magnetic resonance (MR) imaging and F-18 FDG PET has been reported to be superior to CT. However, studies on direct comparison of PET and MR are scarce. We compared the diagnostic accuracy of FDG PET and MR in detecting liver metastasis from colorectal cancer. Materials and Methods: Among 363 colorectal cancer patients who underwent F-18 FDG PET (ECAT, Siemens-CTI, Knoxville; Gemini, Philips, Milpitas, U.S.), 26 patients (M:F=17:9, age=$62{\pm}11$) underwent MR to evaluate suspicious metastatic liver lesions. Finally, 35 liver lesions detected by CT from 26 patients were enrolled for analysis. PET and MR results were compared with pathologic reports, clinical findings or follow-up results. Results: Of the 35 lesions, 18 lesions (51.4%) were diagnosed as liver metastases, while remaining 17 (48.6%) as benign. The sensitivity and the specificity of PET were 94.4% and 94.1%, respectively, compared to 100% and 82.4% for MR. MR and PET was concordant in 30 lesions (85.7%: 17 metastatic (94.4%) and 13 benign (76.5%) lesions. ROC curve analysis revealed maximal SUV of 3.1 as the optimum standard in differentiating metastatic from benign liver lesions (AUC=0.897, p<0.001, sensitivity 83.3%, specificity 94.1%). For small lesions less than 1 cm ln diameter (n=20), diagnostic accuracy of PET was comparable to that of MR. Conclusion: F-18 FDG PET showed good diagnostic performance in detecting liver metastasis from colorectal cancer, which was comparable to MR.

• Journal of the Korean Orthopaedic Association
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• v.55 no.6
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• pp.511-519
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• 2020

Purpose: Schwannoma is a benign tumor that occurs mainly in the peripheral nerve. If the tumor is large or is in areas other than the nerves, it is likely to be mistaken for malignant soft tissue tumors. The authors reviewed 50 cases of giant schwannomas and assessed the distribution of the primary locations, clinical symptoms, radiological and pathological diagnosis, and diagnostic accuracy. Materials and Methods: Of the 214 pathologically confirmed schwannomas, 50 cases with a maximum diameter of 5 cm or more were extracted. The entire cohort was classified into three subgroups (major peripheral nerve, intramuscular, bone) according to the primary location, and the anatomical locations were specified. Results: When the entire cohort was classified according to the primary location, 14 tumors occurred in the major peripheral nerve, 31 cases in the muscle, and 5 cases in the bone. The mean size of the tumor in the entire cohort was 7.0 cm, and the intramuscular subgroup had the largest size with 8.0 cm. The radiological diagnosis revealed 33 out of 50 cases to be benign schwannoma (66.0%), 15 cases as low-grade malignancy (30.0%), and the remaining two cases (4.0%) as a suspicious tuberculosis abscess and tenosynovial giant cell tumor, respectively. On the clinical symptoms, Tinel sign was the most common in the peripheral nerve group with 78.6% (11/14), while 93.5% of the intramuscular group had palpation of the mass with a mean duration of 66.6 months. In the bone group, one out of five cases was reported as a low-grade malignancy. Two cases of postoperative complications were encountered; one was bleeding after tumor excision, which required hemostasis, and the other was peroneal nerve palsy after surgery. Conclusion: When assessing the large-sized soft tissue tumors in the muscles, the possibility of a benign schwannoma should be considered if 1) there is a long period of mass palpation and 2) non-specific findings in MRI. Preoperative pathology confirmation with a biopsy can help reduce the risk of overtreatment.

• The Korean Journal of Nuclear Medicine Technology
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• v.14 no.2
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• pp.9-16
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• 2010

Purpose: With increasing medical use of radiation and radioactive isotopes, there is a need to better manage the risk of radiation exposure. This study aims to grasp and analyze the individual radiation exposure situations of radiation-related workers in a medical facility by specific job, in order to instill awareness of radiation danger and to assist in safety and radiation exposure management for such workers. Materials and Methods: 1 January 2007 to 31 December 2009 to work in medical institutions are classified as radiation workers Nuclear personal radiation dosimeter regularly, continuously administered survey of 40 workers in three years of occupation to target, Imaging Unit beautifully, age, dose sector, job function-related tasks to identify the average annual dose for a deep dose, respectively, were analyzed. The frequency analysis and ANOVA analysis was performed. Results: Imaging Unit beautifully three years the annual dose PET and PET/CT in the work room 11.06~12.62 mSv dose showed the highest, gamma camera injection room 11.72 mSv with a higher average annual dose of occupation by the clinical technicians 8.92 mSv the highest, radiological 7.50 mSv, a nurse 2.61 mSv, the researchers 0.69 mSv, received 0.48 mSv, 0.35 mSv doctors orderly, and detail work employed the average annual dose of the PET and PET/CT work is 12.09 mSv showed the highest radiation dose, gamma camera injection work the 11.72 mSv, gamma camera imaging work 4.92 mSv, treatment and safety management and 2.98 mSv, a nurse working 2.96 mSv, management of 1.72 mSv, work image analysis 0.92 mSv, reading task 0.54 mSv, with receiving 0.51 mSv, 0.29 mSv research work, respectively. Dose sector average annual dose of the study subjects, 15 people (37.5%) than the 1 mSv dose distribution and 5 people (12.5%) and 1.01~5.0 mSv with the dose distribution was less than, 5.01~10.0 mSv in the 14 people (35.0%), 10.01~20.0 mSv in the 6 people (15.0%) of the distribution were analyzed. The average annual dose according to age in occupations that radiological workers 25~34 years old have the highest average of 8.69 mSv dose showed the average annual dose of tenure of 5~9 years in jobs radiation workers in the 9.5 mSv The average was the highest dose. Conclusion: These results suggest that medical radiation workers working in Nuclear Medicine radiation safety management of the majority of the current were carried out in the effectiveness, depending on job characteristics has been found that many differences. However, this requires efforts to minimize radiation exposure, and systematic training for them and for reasonable radiation exposure management system is needed.

• The Korean Journal of Nuclear Medicine
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• v.35 no.1
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• pp.52-60
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• 2001

Purpose: In young male patients who suffered several kinds of trauma with subsequent suspicious reflex sympathetic dystrophy syndrome, we performed three-phasic bone scan in order to investigate its usefulness. Materials and Methods: Patients with narrow range of age (21-25. mean $22.8{\pm}1.3$, all male) were included with suspicious reflex sympathetic dystrophy syndrome of 12 feet and 5 hands. Only one was bilateral feet case and 16 were ipsilateral (Rt:13, Lt:3). The etiologic traumas were 4 fractures, 4 sprains, 3 blunt trauma, 2 cellulitis, 1 tendon tear, 1 crush injury, 1 overexercise, and 1 unknown. Radiologically 3 showed osteoporotic changes. Three-phasic bone scans were performed $21.2{\pm}7.3wks$ after trauma. Results: According to symptom complex, confirmatory reflex sympathetic dystrophy syndrome 4 cases and suspicious 13 were analyzed. All confirmatory cases (100%) showed increased uptake at delay phase with periarticular accentuation. Of confirmatory 4 cases, 2 showed increased uptake in all three phases (perfusion: P, blood pool: B, and delay: D), and other 2 revealed decreased P but, both increased B and D. Of suspicious 13 cases, 9(69.2%) had increased D (4 periarticular and 5 focal), 2 decreased D, and 2 symmetric D. In 12 foot cases, so-called weight hearing patterns - increased contralateral sole at P and B - were revealed in 7(58.3%). Conclusion: Diffuse periarticular increased uptake at delay phase of three-phasic bone scan was a compatible finding to reflex sympathetic dystrophy syndrome in young male patients whose symptom complex strongly designated post traumatic reflex sympathetic dystrophy syndrome.

• Journal of Veterinary Clinics
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• v.31 no.2
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• pp.152-155
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• 2014

An 11-year-old castrated Schnauzer presented with paraplegia for the last two weeks, initially developed pelvic limb ataxia 6 months ago and left pelvic limb paresis 3 months ago. On neurological examination, paraplegia and postural reaction deficits were noted in the pelvic limbs with no deep pain sensation, and the dog showed exaggerated spinal reflexes and involuntary urination. Magnetic resonance (MR) images of thoracolumbar spinal cord were obtained with a 0.3 Tesla magnet. A mass with a broad base to the dorsal and left dural margins was identified at the level of L2, causing marked spinal cord compression. The mass showed isointensity to the spinal cord on T1-weighted (T1W) precontrast images, hyperintensity on T2-weighted images, marked homogeneous contrast enhancement with well-defined margins and the "dural tail" sign on T1W postcontrast images. An intradural-extramedullay tumor was considered, most likely, meningioma was highly suggestive. Left-sided hemilaminectomy and dorsal laminectomy were performed. An intradural mass partially adherent to dura mater was compressing the spinal cord, and the mass was completely removed with the attached dura mater. A histopathologic diagnosis of angiomatous subtype meningioma was made.

• Investigative Magnetic Resonance Imaging
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• v.17 no.1
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• pp.19-25
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• 2013

Purpose : Renal blood oxygen level-dependent (BOLD) MRI has been used in the evaluation of renal oxygenation. We tried to provide the normal $R2^*$ value of the human kidney with 3.0 T, and evaluated the differences in $R2^*$ values according to gender and location. Materials and Methods: Twenty-four healthy volunteers underwent BOLD MRI at 3.0 T. Multi gradient echo-echo planar imaging sequence with seventeen echoes was used. After generation of the $T2^*$ map, the $R2^*$ was calculated. The statistical differences in $R2^*$ values between the cortex and medulla, males and females, and the right and left kidney were analyzed. The regional differences of $R2^*$ within the both kidneys were evaluated respectively. Results: BOLD MRI was successful in all participants. No gross artifact interfered with $R2^*$ measurement. The mean $R2^*$ at 3.0 T was $17.1{\pm}2.60s^{-1}$ in the cortex and $27.7{\pm}4.83s^{-1}$ in the medulla (p < 0.001). The $R2^*$ value in the medulla was significantly higher in the male than female volunteers (p = 0.025). There were no statistical differences of $R2^*$ according to the side and location in the kidney (p = 0.197). Conclusion: Renal BOLD MRI can be efficiently performed with 3.0 T MRI. Renal medullary hypoxia is present in normal volunteers. Our results may be used as reference values in the evaluation of pathologic conditions using BOLD MRI.

• The Journal of the Korean bone and joint tumor society
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• v.15 no.1
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• pp.34-43
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• 2009

Purpose: Glomus tumors are rare benign vascular tumors, usually located in the skin or soft tissue of extremities. Approximately 30-50% of glomus tumors occur in subungal area, but glomus tumors have been described in every location even where glomus bodies are not or rarely present. The purpose of this study was to identify clinical, histologic and MRI characteristics of soft tissue glomus tumor. Materials and Methods: Between 1993 and 2008, eight patients underwent surgery of soft tissue Glomus tumor at our institution. Exclusion criteria were patients with Glomus tumors in digits, stomach, trachea and glomus tympanicum. We analyzed medical records, interviews, physical examinations, MR findings and histolocial types retrospectively. Results: There were four men and four women. The mean age was fourty-seven years. The mean prevalence time was eight-point-nine years. In the classic triad of symptoms, all eight patients had pain and tenderness. Two patients complained of cold sensitivity. Two showed skin color changes. After surgery, two showed symptom improvement (VAS $9^{\circ}{\rightarrow}8$, $8^{\circ}{\rightarrow}5$) and?six showed complete disappearance of symptoms. Slightly symptom improvemented (VAS $9^{\circ}{\rightarrow}8$) one had additional surgery two times after first surgery due to relapse/remaining Glomus tumor. The mean size was 13.9 mm. In histology, six were 'solid glomus tumor', one was a mixture of 'solid glomus tumor' and 'lomangioma' and one was 'malignant glomus tumor'. MR findings showed isointense signal on T1 image, high signal on T2 image and strong enhancement on the Gadolinium enhanced image. Conclusion: Glomus tumor has low recurrence rate and malignant change, rapid diagnosis and surgical excision is critical in treatment to prevent unnecessary pain of patient.