• The Korean Journal of Nuclear Medicine
• /
• v.27 no.2
• /
• pp.175-182
• /
• 1993

We evaluated the usefulness of $^{99m}Tc$-HMPAO SPECT in 21 Patients with subarachnoid hemorrhage due to ruptured intracranial aneurysm and in 3 patients with unruptured intracranial aneurysm. SPECT study could detect the bilaterally hypoperfused cases in 10 patients (48%), but CT/MRI showed the bilateral abnormalities in only 3 patients (14%). The number of abnormal lesions were 56 in SPECT and 25 in CT/MRI. The lesions found in SPECT were well correlated with the neurological signs of the patients such as aphasia or hemiplegia. SPECT study during Matas test was helpful in evaluating the risk for carotid artery occlusion therapy. We thought that $^{99m}Tc$-HMPAO brain SPECT is helpful in evaluating the functional changes in patients with subarachnoid hemorrhage.

• Journal of the Korean Society of Radiology
• /
• v.5 no.6
• /
• pp.315-324
• /
• 2011

The purpose of this study was to use as basic data for the is systematic and efficient facility inventory of policeman and the riot police, conscripted policeman. First, the analysis was performed for the patient implementing the simple x-ray, CT, and MRI examination to the policeman and the riot police, conscripted policeman within the radiologic examination. As to the classification by disease, it classified into the partial body as the common disease and musculoskeletal system disease. As to the fixed quantity comparison of the policeman and the riot police, conscripted policeman the basic X-ray, CT, MRI examination by part average personnel was compared. As to the research result the riot police, conscripted policeman, the Lower extremity examination occupies the simple X-ray, CT, and MRI examination in comparison with the other part altogether much and particularly, the Knee examination ratio occupies much among the Lower extremity examination.

• The Korean Journal of Nuclear Medicine
• /
• v.30 no.4
• /
• pp.516-523
• /
• 1996

The purpose of this study was to evaluate the clinical usefulness of I-123 MIBG scintigraphy with early planar and SPECT image in the diagnosis of neuroendocrine tumors. We reviewed I-123 MIBG scintigraphies of 21 patients who had been suspected to have neuroendocrine tumors by CT or MRI findings. Early 4 hour planar and SPECT images were obtained in all patients and delayed (13-24 hour) planar images were performed in 17 patients. Final diagnoses were made by surgery, biopsy, or clinical follow up. Twelve patients were confirmed to have neuroendocrine tumors. With 4 hour planar and SPECT images, there were 9 true positives(6 pheochromocytomas, 1 paraganglioma, 1 neuroblastoma, and 1 medullary cancer of the thyroid), 8 true negatives(1 adrenal cortical adenoma, 1 malignant fibrous histiocytoma, 1 adenoma in colon and 5 benign nonfunctioning adrenal tumors), 1 false positive(hepatocellular carcinoma) and 3 false negatives(1 recurred medullary cancer of the thyroid, 1 liver metastasis of carcinoid tumor and 1 ganglioneuroma). The sensitivity and specificity of I-123 MIBG scintigraphy were 75% and 89%, respectively. SPECT images provided good anatomical correlation with CT or MRI. Delayed images showed increased tumor to background ratio in 5 out of 8 true positive patients, but did not change the diagnosis. In conclusion, early 4 hour images with I-123 MIBG is clinically convenient and useful method in the detection of neuroendocrine tumors, and SPECT images can provide good anatomical correlation with CT or MRI.

• The Korean Journal of Nuclear Medicine
• /
• v.28 no.1
• /
• pp.17-21
• /
• 1994

We studied 115 patients with seizure who had been performed brain SPECT, brain MRI or CT and EEG. To evaluate the pattern of brain SPECT in seizure patients 28 of them had secondary epilepsies, 87 had primary epilepsies. In primary epilepsies, 42 were generalized seizure and 45 were partial seizure. The causes of secondary epilepsies were congenital malformation, cerebromalacia, cerebral infarction, multiple sclerosis, AV-malformation, granuloma and etc, in order. In 28 secondary epilepsies, 25 of them, brain SPECT lesions was concordant with MRI or CT lesions, 3 were disconcordant. The brain SPECT findings of generalized seizure were normal in 22 patients, diffuse irregular decreased perfusion in 8, decreased in frontal cortex in 4, temporal in 5 and frontotemporal in 3. In 45 partial seizure, 19 brain SPECT were concordant with EEG (42.4%).

• Journal of the Korean Society of Radiology
• /
• v.82 no.1
• /
• pp.152-161
• /
• 2021

Purpose To evaluate the incidence and condition of platysma infiltration in benign tumors, malignant tumors, and inflammatory disease in the parotid gland using CT or MRI. Materials and Methods Patients with benign tumors (n = 314), malignant tumors (n = 52), and inflammatory disease (n = 22) in the parotid gland were included. The incidence of platysma infiltration and the relationship between platysma infiltration and the location, capsular involvement, and focality of the mass were retrospectively evaluated using CT or MRI. Results The incidence of platysma infiltration was 0% in benign tumors,19.2% in malignant tumors (10/52), and 50.0% in inflammation (11/22). Platysma infiltration was positive in 10 of 13 patients with inflammatory lesion with capsular involvement. Platysmal infiltrations in inflammatory lesion showed diffuse lesion in 10 patients and focal lesion in one patient. Malignant tumor with platysmal infiltration showed all capsular involvement, and diffuse lesion in seven and focal lesion in three. Conclusion Platysma infiltration was more common in patients with inflammatory disease than those with malignant tumors or benign tumors. In inflammatory disease, platysma infiltration was more common in patients with capsular involvement or diffuse lesion.

• Korean Journal of Head & Neck Oncology
• /
• v.26 no.1
• /
• pp.14-18
• /
• 2010

Objectives : We evaluated the use of FDG PET/CT for the identification of cervical nodal metastases of SCC of the oral cavity and oropharynx with histological correlation. Material and Methods : We reviewed 46 medical records, from January 2004 to July 2007, of patients who underwent FDG PET/CT and CT/MRI for SCC of the oral cavity and oropharynx before surgery. We recorded the lymph node metastases according to the neck level affected and the system used for the imaging-based nodal classification. Results : The FDG PET/CT had a sensitivity of 75.6% and a specificity of 96.7% ; it had a higher sensitivity than the CT/MRI for identification of cervical metastases on the side of the neck(26/28 vs. 20/28, p=0.031) and at each of the cervical levels(34/45 vs. 26/45, p=0.008). There was a significant difference in the $SUV_{max}$ between the benign and malignant cervical lymph nodes($3.31{\pm}3.23$ vs. $4.22{\pm}2.57$, p=0.028). The receiver-operating-characteristic (ROC) curve analysis for differentiating the benign from the malignant cervical lymph nodes, showed that the area under the curve(AUC) of the FDG PET/CT was 0.775. The cut-off value for the $SUV_{max}$ was 2.23 based on the ROC curve. There was a significant correlation between the $SUV_{max}$ and the size of the cervical lymph nodes(Spearman r=0.353, p=0.048). Conclusion : FDG PET/CT images were more accurate than the CT/MRI images. In addition, the $SUV_{max}$ cut-off values were important for evaluating cervical the cervical nodes in the patients with SCC of the oral cavity and oropharynx.

• Journal of radiological science and technology
• /
• v.32 no.2
• /
• pp.195-203
• /
• 2009

Image registration is a fundamental task in image processing used to match two or more images. It gives new information to the radiologists by matching images from different modalities. The objective of this study is to develop 2D image registration algorithm for PET/CT and CT images acquired by different systems at different times. We matched two CT images first (one from standalone CT and the other from PET/CT) that contain affluent anatomical information. Then, we geometrically transformed PET image according to the results of transformation parameters calculated by the previous step. We have used Affine transform to match the target and reference images. For the similarity measure, mutual information was explored. Use of particle swarm algorithm optimized the performance by finding the best matched parameter set within a reasonable amount of time. The results show good agreements of the images between PET/CT and CT. We expect the proposed algorithm can be used not only for PET/CT and CT image registration but also for different multi-modality imaging systems such as SPECT/CT, MRI/PET and so on.

• Korean Journal of Radiology
• /
• v.22 no.5
• /
• pp.714-724
• /
• 2021

Objective: To evaluate the value of ¹⁸F-fluorodeoxyglucose PET/MRI added to contrast-enhanced CT (CECT) in initial staging, assessment of resectability, and postoperative follow-up of biliary tract cancer. Materials and Methods: This retrospective study included 100 patients (initial workup [n = 65] and postoperative follow-up [n = 35]) who had undergone PET/MRI and CECT for bile duct or gallbladder lesions between January 2013 and March 2020. Two radiologists independently reviewed the CECT imaging set and CECT plus PET/MRI set to determine the likelihood of malignancy, local and overall resectability, and distant metastasis in the initial workup group, and local recurrence and distant metastasis in the follow-up group. Diagnostic performances of the two imaging sets were compared using clinical-surgical-pathologic findings as standards of reference. Results: The diagnostic performance of CECT significantly improved after the addition of PET/MRI for liver metastasis (area under the receiver operating characteristic curve [A_z]: 0.77 vs. 0.91 [p = 0.027] for reviewer 1; 0.76 vs. 0.92 [p = 0.021] for reviewer 2), lymph node metastasis (0.73 vs. 0.92 [p = 0.004]; 0.81 vs. 0.92 [p = 0.023]), and overall resectability (0.79 vs. 0.92 [p = 0.007]; 0.82 vs. 0.94 [p = 0.021]) in the initial workup group. In the follow-up group, the diagnostic performance of CECT plus PET/MRI was significantly higher than that of CECT imaging for local recurrence (0.81 vs. 1.00 [p = 0.029]; 0.82 vs. 0.94 [p = 0.045]). Conclusion: PET/MRI may add value to CECT in patients with biliary tract cancer both in the initial workup for staging and determination of overall resectability and in follow-up for local recurrence.

• Journal of Veterinary Clinics
• /
• v.40 no.5
• /
• pp.370-374
• /
• 2023

Oral melanoma is the most common type of oral tumor in dogs. In this report, computed tomography (CT) and magnetic resonance imaging (MRI) were performed to diagnose a right oral pigmented mass in an 8-year-old dog. The oral mass appeared as a homogeneous soft tissue density parenchyma on pre-contrast CT images, and with heterogeneous enhancement on post-contrast images. Bone destruction of the right mandibular body around the mass and mild enlargement of the right mandibular lymph node were also found. On MRI, the bulky oral mass showed mixed hyperintensity and isointensity compared to the adjacent muscle, where irregular hyperintensity on T1-weighted images corresponded to hypointensity on the T2-weighted images. Based on the physical examinations and imaging results, melanoma was suspected and confirmed via fine-needle aspiration. These unique MRI signals were due to the high paramagnetic melanin content in the tumor, therefore MRI examination could be useful for diagnosis of melanoma.

• Korean Journal of Radiology
• /
• v.20 no.6
• /
• pp.863-879
• /
• 2019

Hepatocellular carcinoma (HCC) can be noninvasively diagnosed on the basis of its characteristic imaging findings of arterial phase enhancement and portal/delayed "washout" on computed tomography (CT) and magnetic resonance imaging (MRI) in cirrhotic patients. However, different specific diagnostic criteria have been proposed by several countries and major academic societies. In 2018, major guideline updates were proposed by the Association for the Study of Liver Diseases, European Association for the Study of the Liver (EASL), Korean Liver Cancer Association and National Cancer Center (KLCA-NCC) of Korea. In addition to dynamic CT and MRI using extracellular contrast media, these new guidelines now include magnetic resonance imaging (MRI) using hepatobiliary contrast media as the first-line diagnostic test, while the KLCA-NCC and EASL guidelines also include contrast-enhanced ultrasound (CEUS) as the second-line diagnostic test. Therefore, hepatobiliary MR contrast media and CEUS will be increasingly used for the noninvasive diagnosis and staging of HCC. In this review, we discuss the emerging role of hepatobiliary phase MRI and CEUS for the diagnosis of HCC and also review the changes in the HCC diagnostic criteria in major guidelines, including the KLCA-NCC practice guidelines version 2018. In addition, we aimed to pay particular attention to some remaining issues in the noninvasive diagnosis of HCC.