• Journal of Veterinary Clinics
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• v.30 no.3
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• pp.206-209
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• 2013

A 12-year-old castrated male Miniature Schnauzer dog was presented with an acute seizure. On computed tomography, a mass was observed in the left nasal cavity and the lysis of the left cribriform plate was identified. Post-contrast magnetic resonance imaging showed a hyperintense mass in the left frontal lobe and hyperintense lesions in the left frontal sinus. The mass was tentatively diagnosed with a brain tumor secondary to a nasal tumor. Histopathology revealed that the mass was a nasal adenocarcinoma with invasion into the brain. This case report describes clinical, computed tomography, magnetic resonance imaging and histopathological findings of secondary intracranial tumor caused by extension of nasal adenocarcinoma in a dog. These findings may contribute to enhance the knowledge on secondary intracranial tumors in dogs.

• Journal of Radiopharmaceuticals and Molecular Probes
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• v.1 no.2
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• pp.137-144
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• 2015

Hypoxia is an important adverse prognostic factor for tumor progression and is a major cause of failure of radiation therapy. In case of short-term hypoxia, the metabolism can recover to normal, but if hypoxia persists, it causes irreversible cell damage and finally leads to death. So a hypoxia marker would be very useful in oncology. In particular, 2-nitroimidazole can be reduced to form a reactive chemical species, which can bind irreversibly to cell components in the absence of sufficient oxygen, thus, the development of radiolabeled nitroimidazole derivatives for the imaging of hypoxia remains an active field of research to improve cancer therapy result. 2-nitroimidazole based hypoxia marker, [$^{18}F$]FMISO holds promise for the evaluation of tumor hypoxia by Positron emission tomography (PET), at both global and local levels. In the present study, [$^{18}F$]FMISO was synthesized using an automatic synthesis module with high radiochemical purity (>99%) in 60 min. Immunohistochemical analysis using pimonidazole confirmed the presence of hypoxia in xenografted CT-26 tumor tissue. A biodistribution study in CT-26 xenografted mice showed that the increased tumor-to-muscle ratio and tumor-to-blood ratios from 10 to 120 min post-injection. In the PET study, [$^{18}F$]FMISO also showed increased tumor-to-muscle ratios from 10 to 120 min post-injection. In conclusion, this study demonstrates the feasibility and utility of [$^{18}F$]FMISO for imaging hypoxiain mouse colon cancer model using small animal PET.

• Korean Journal of Radiology
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• v.22 no.9
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• pp.1462-1474
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• 2021

There are various diseases of the gallbladder and cystic duct, and imaging diagnosis is challenging for the rare among them. However, some rare diseases show characteristic imaging findings or patient history; therefore, familiarity with the imaging presentation of rare diseases may improve diagnostic accuracy and patient management. The purpose of this article is to describe the imaging findings of rare diseases of the gallbladder and cystic duct and identify their pathological correlations with these diseases.

• Journal of Korean Neurosurgical Society
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• v.41 no.6
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• pp.371-376
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• 2007

Objective : The aim of this study was to investigate the usefulness of diffusion-weighted imaging [DWI] and apparent diffusion coefficiency [ADC] in distinguishing brain abscesses from cystic or necrotic brain tumors, which are difficult to be differentiated by conventional magnetic resonance imaging techniques. Methods : Seven patients with brain abscesses and ten patients with cystic brain tumors were studied from September 2003 to October 2005. Abscess, subdural empyema and ventriculitis were categorized to the abscess group and cystic or necrotic brain gliomas or metastatic brain tumors into the tumor group. Preoperative magnetic resonance images were performed in all patients and diffusion-weighted images and apparent diffusion coefficiency values of lesions were calculated directly from software of 1.5 tesla MRI [General Electrics, USA]. The ratio of the ADC of the lesion to contralateral regional ADC was also measured [relative ADC, rADC]. Results : The average ADC value of pyogenic abscesses group was $0.82+/-0.14{\times}10^{-3}\;[mean+/-S.D.]\;mm^2/s$ and mean rADC was 0.75. Cystic or necrotic areas had high ADC values [$2.49+/-0.79{\times}10^{-3}\;mm^2/s$, mean rADC=2.14]. ADC and rADC values of abscesses group showed about three times lower values than those of cystic or necrotic tumor group. Conclusion : This study results based on numerical comparison of signal intensities and quantitative analysis to distinguish between brain abscess and cystic or necrotic tumor, DWI and ADC mapping are thought to be very useful diagnostic tools.

• Korean Journal of Radiology
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• v.20 no.1
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• pp.18-33
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• 2019

In this study, we summarize the clinical role of magnetic resonance imaging (MRI) in the diagnosis of patients with malignant uterine neoplasms, including leiomyosarcoma, endometrial stromal sarcoma, adenosarcoma, uterine carcinosarcoma, and endometrial cancer, with emphasis on the challenges and disadvantages. MRI plays an essential role in patients with uterine malignancy, for the purpose of tumor detection, primary staging, and treatment planning. MRI has advanced in scope beyond the visualization of the many aspects of anatomical structures, including diffusion-weighted imaging, dynamic contrast enhancement-MRI, and magnetic resonance spectroscopy. Emerging technologies coupled with the use of artificial intelligence in MRI are expected to lead to progressive improvement in case management of malignant uterine neoplasms.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.11
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• pp.6337-6340
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• 2013

Through retrospective analysis of 13 cases of magnetic resonance image (MRI) manifestations of atypical meningiomas confirmed by operation and pathology in the First Affiliated Hospital of Xinxiang Medical University, the objective of this study was to evaluate the diagnostic value of MRI in order to improve the accuracy rate of preoperative diagnosis. In this retrospective analysis of MRI findings for atypical meningiomas in First Affiliated Hospital of Xinxiang Medical University from January to July in 2012, the location, morphology and tumor signals and other tumor imaging characteristics were covered. In 13 cases of atypical meningioma patients of this group, most tumors were located at typical sites (10/13), mainly the falx cerebri, parasagittal, convexity, saddle area. Only two cases were at atypical locations, 1 in the cerebellar hemisphere and 1 in a lateral ventricle. Most of the tumors showed T1 and T2 isointensity signals, and necrosis, calcification, and peritumoral edema were always featured. DWI showed isointensity in 11 cases (11/13), and hyperintensity in 2. Some 9 cases had dural tail signs, 12 had accurate positioning (12/13), and 2 were postoperative recurrences. MRI has high value in the diagnosis of atypical meningiomas, with important roles in early clinical diagnosis, treatment and prognosis evaluation.

• Investigative Magnetic Resonance Imaging
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• v.23 no.1
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• pp.34-37
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• 2019

Gadolinium contrast agents (CAs) are integral components of clinical magnetic resonance imaging (MRI). However, safety concerns have arisen regarding the use of gadolinium CAs, due to their association with nephrogenic systemic fibrosis (NSF). Furthermore, recently the long-term retention of $Gd^{3+}-based$ CAs in brains patients with normal renal function raised another possible safety issue. The safety concerns of $Gd^{3+}-based$ CAs have been based on the ligand structure of $Gd^{3+}-based$ CAs, and findings that $Gd^{3+}-based$ CAs with linear ligand structures showed much higher incidences of NSF and brain retention of CAs than $Gd^{3+}-based$ CAs with macrocyclic ligand structure. In the current study, we report the in vivo biodistribution profile of a new highly stable multifunctional $Gd^{3+}-based$ CA, with macrocyclic ligand structure (HNP-2006). MR imaging using HNP-2006 demonstrated a significant contrast enhancement in many different organs. Furthermore, the contrast enhanced tumor imaging using HNP-2006 confirmed that this new macrocyclic CA can be used for detecting tumor in the central nervous system. Therefore, this new multifunctional HNP-2006 with macrocyclic ligand structure shows great promise for whole-body clinical application.

• Journal of Veterinary Science
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• v.19 no.6
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• pp.827-834
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• 2018

The purpose of this study was to evaluate the clinical and imaging characteristics of canine splenic tumors and to establish guidelines for the presurgical assessment of splenic tumors in dogs. Fifty-seven dogs that underwent total splenectomy for the treatment of splenic tumors were evaluated by examining medical records, hematologic results, diagnostic imaging results, and histopathologic results. The maximum lesion size from ultrasonography was significantly different between malignant and benign tumors (p = 0.002). There was a correlation between tumor margination and type of splenic tumors (p = 0.045). Precontrast lesion attenuation on computed tomography was significantly different between splenic malignant and benign tumors (p = 0.001). The mean ${\pm}$ SD precontrast lesion attenuation of malignant tumors was $40.3{\pm}5.9$ Hounsfield units (HU), and for benign tumors, it was $52.8{\pm}6.8HU$. In conclusion, some variables of the imaging examination could be used to distinguish the type of splenic tumor. Based on the study results, using a diagnostic flowchart would be effective in increasing the survival rate of patients with splenic malignant tumors. In addition, fine needle aspiration or magnetic resonance imaging prior to surgical exploration and histopathologic examination may be useful in achieving a more accurate diagnosis.

• Journal of Korean Neurosurgical Society
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• v.57 no.6
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• pp.478-483
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• 2015

We report two rare cases of spinal intraosseous schwannoma (SIS) with sustained myelopathy symptoms and provide an updated review regarding SIS in the literature. A 71-year-old man experienced right lumbocrural pain and gait disturbance accompanied with paresthesia and right leg weakness. Imaging examinations revealed a mass with lesions in L4 vertebral body causing bone destruction and spinal cord compression. Complete resection of the well-demarcated tumor and posterior fusion were performed. A 54-year-old female reported bilateral gait disturbance, paresthesia, and numbness without weakness, and imaging revealed a posterior mass from T9 causing spinal cord compression and bone erosion. The tumor was completely separated from the spinal nerve root. The tumors from both patients were confirmed as schwannomas. Tumor recurrence was not observed at the 2-4 year follow-up. Although rare, SIS should be considered during differential diagnosis and can affect treatment planning. SIS symptoms vary depending on tumor location, and fusion is frequently necessary for spinal reconstruction after complete tumor resection.

• Journal of Korean Neurosurgical Society
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• v.52 no.2
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• pp.148-151
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• 2012

Intracranial squamous cell carcinoma is extremely rare, with most of the cases arising from malignant transformation of an epidermoid or a dermoid cyst. The patient presented with facial weakness. Initial magnetic resonance imaging revealed a mass in the right cerebellopontine angle. A subtotal resection was performed via right retrosigmoid suboccipital approach. Histopathological findings were consistent with an epidermoid tumor. Five months later, the patient underwent gamma knife radiosurgery due to highly probable recurrent epidermoid tumor. Two years after, the patient's neurological deficit had been newly developed, and follow-up magnetic resonance imaging demonstrated a large contrast-enhancing tumor in the left cerebellopontine angle, which compressed the brainstem. After resection of the tumor, histopathological examinations revealed a squamous cell carcinoma probably arising from an underlying epidermoid cyst. We report a case of an epidermoid tumor in the cerebellopontine angle that transformed into a squamous cell carcinoma.