• Investigative Magnetic Resonance Imaging
• /
• v.14 no.2
• /
• pp.151-155
• /
• 2010

Primary hepatic lymphoma is extremely rare, representing less than 1% of all extranodal lymphomas. We report MR imaging features and pathologic correlation of a case of primary hepatic lymphoma. MR images showed a large lobulated mass with gradual contrast enhancement, resembling intrahepatic cholangiocarcinoma. However, both hepatobiliary phase image obtained 20 minutes after injection of hepatocyte specific contrast agent and diffusion-weighted image demonstrated characteristic three layered pattern representing viable lymphoma in the outer layer, tumor necrosis in the middle layer and necrotic hepatic parenchyma in the center.

• Korean Journal of Radiology
• /
• v.2 no.3
• /
• pp.151-158
• /
• 2001

Objective: To determine the ability of MR imaging to detect the pathological changes occurring in radiofrequency (RF) thermal lesions and to assess its accuracy in revealing the extent of tissue necrosis. Materials and Methods: Using an RF electrode, thermal lesions were created in the livers of 18 rabbits. The procedure involved three phases. In the acute phase, six animals were killed the day after performing thermal ablation with RF energy, and two on day 3. In the subacute and chronic phases, eight rabbits underwent percutaneous hepatic RF ablation. After performing MR imaging, two animals were sacrificed at 1, 2, 4, and 7 weeks after the procedure, and MRpathologic correlation was performed. Results: In the acute phase, the thermal ablation lesions appeared at gross examination as well-circumscribed, necrotic areas, representing early change in the coagulative necrosis seen at microscopic examination. They were hypointense on T2-weighted images, and hyperintense on T1-weighted images. Gadolinium-enhanced MR imaging showed that a thin hyperemic rim surrounded the central coagulative necrosis. In the subacute phase, ablated lesions also showed extensive coagulative necrosis and marked inflammation at microscopic examination. Beyond two weeks, the lesions showed gradual resorption of the necrotic area, with a peripheral fibrovascular rim. The size of lesions measured by MR imaging correlated well with the findings at gross pathologic examination. Conclusion: MR imaging effectively demonstrates the histopathological tissue change occurring after thermal ablation, and accurately determines the extent of the target area.

• Childhood Kidney Diseases
• /
• v.21 no.2
• /
• pp.47-52
• /
• 2017

Purpose: Renal ultrasonography has been widely used in children with renal disease. However, the relationship of renal echogenicity with renal pathology and function in children is not well known. Method: Ultrasound examination was performed in 75 patients undergoing renal biopsy for suspected renal disease in Konkuk University Medical Center from August 2005 to November 2015. We compared renal echogenicity to pathologic findings and renal function. Renal echogenicity was scored as 0 to 2 by comparing adjacent liver echogenicity. Three histologic characteristics were evaluated: glomerular changes, interstitial infiltration or fibrosis, and tubular atrophy. These were graded as 0 to 3, according to increasing severity. Laboratory results included urine albumin excretion and estimated glomerular filtration rate (eGFR). Results: Among pathologic findings, renal echogenicity revealed a positive correlation with interstitial infiltration or fibrosis (r=0.259, P=0.025), and with tubular atrophy (r=0.268, P=0.02). Renal echogenicity and glomerular changes were not correlated. Renal echogenicity showed a positive correlation with microalbuminuria (r=0.283, P=0.014), but a negative correlation with eGFR (r=-0.352, P=0.002). Conclusion: Increased renal echogenicity suggested severe interstitial infiltration or fibrosis and tubular atrophy among the pathologic findings. Moreover, increased echogenicity is correlated with increased urine albumin excretion and decreased eGFR. Echogenicity on ultrasonography is useful for determining the status of renal pathology and function.

• Investigative Magnetic Resonance Imaging
• /
• v.18 no.4
• /
• pp.279-289
• /
• 2014

Objective: The aims of this article are to differentiate soft tissue masses showing low signal intensity on T2-weighted images (T2WIs) according to the histopathologic findings. Conclusion: To know relatively small numbered soft tissue masses with low signal intensities on T2WIs adding characteristic location, morphology, signal intensities on other sequences might be helpful for differential diagnosis of mostly non-specific soft tissue tumors on MRI.

• Investigative Magnetic Resonance Imaging
• /
• v.19 no.4
• /
• pp.241-247
• /
• 2015

Arteriovenous malformation (AVM) of the pancreas is extremely rare, although it may be increasingly diagnosed due to the widespread use of cross-sectional imaging of the abdomen. Early diagnosis of this disease is important to prevent delay of treatment and resulting fatal complications. We report a rare case of pancreatic AVM in a 48-year-old man who presented with severe chronic anemia and early gastric cancer, which made diagnosis challenging. Imaging findings, including ultrasound, computed tomography, and magnetic resonance imaging, are shown, as well as the pathologic features.

• Imaging Science in Dentistry
• /
• v.44 no.3
• /
• pp.193-198
• /
• 2014

Purpose: The present study was aimed to investigate the variation of soft palate morphology in different age and gender groups. The correlations of radiographic velar length (VL), velar width (VW), pharyngeal depth (PD), and Need's ratio with soft palate variants were also studied in the North Indian subpopulation. Materials and Methods: The study sample consisted of 300 subjects aged between 15 and 45 (mean: 31.32) years. The velar morphology on lateral cephalograms was examined and grouped into six types. The results obtained were subjected to a statistical analysis to find the correlation between variants of the soft palate with gender and different age groups. Results: The most frequent type of soft palate was leaf shaped (48.7%), and the least common was crook shaped (3.0%) among both the genders and various age groups, showing a significant correlation. The mean VL, VW, and PD values were significantly higher in males and significantly correlated with the types of soft palate. A significant correlation was observed between the mean VL, VW, PD, and Need's ratio with various age groups, showing an inconsistent pattern with an increase in age. The types of soft palate, gender, and Need's ratio were also significantly correlated, with an overall higher mean value of the Need's ratio among female subjects and the S-shaped soft palate. Conclusion: The knowledge of a varied spectrum of velar morphology and the variants of the soft palate help in a better understanding of the velopharyngeal closure and craniofacial anomalies.

• Korean Journal of Radiology
• /
• v.21 no.5
• /
• pp.598-604
• /
• 2020

Objective: Proper management of lymph nodes (LNs) with ultrasonographic (US) indeterminate features in thyroid cancer patients remains elusive. We aimed to evaluate the malignancy risk and US findings predictive of malignancy for US indeterminate LNs in preoperative thyroid cancer patients through node-by-node correlation. Materials and Methods: A total of 348 LNs in 284 thyroid cancer patients, who underwent fine-needle aspiration or core-needle biopsy between December 2006 and June 2015, were included. We determined the malignancy risks for US probably benign, indeterminate, and suspicious categories. For US indeterminate LNs, which had neither echogenic hilum nor hilar vascularity in the absence of any suspicious finding, US findings were compared between benign and metastatic LNs using Mann-Whitney U test and Fisher's exact test. Results: US imaging diagnoses were probably benign in 20.7% (n = 72) cases, indeterminate in 23.6% (n = 82), and suspicious in 55.7% (n = 194). Malignancy risk of US indeterminate LNs (19.5% [16/82]) differed from those of the US probably benign (2.8% [2/72]) (p = 0.002) and US suspicious LNs (78.4% [152/194]) (p < 0.001). Among US indeterminate LNs, there were no significant differences in short, long, and long-to-short diameter (L/S) ratios between benign and metastatic LNs (3.9 vs. 3.8 mm, p = 0.619; 7.3 vs. 7.3 mm, p = 0.590; 1.9 vs. 1.9, p = 0.652). Conclusion: US indeterminate LNs were frequently encountered during preoperative evaluation and had intermediate malignancy risk. Given the lack of discriminative power of size criteria and L/S ratio, clinical factors such as surgical strategy and node size should be considered for proper triage of US indeterminate LNs in thyroid cancer.

• Korean Journal of Radiology
• /
• v.23 no.11
• /
• pp.1102-1111
• /
• 2022

Objective: To evaluate the ultrasonography (US) features for diagnosing metastasis in cervical lymph nodes (LNs) in patients with thyroid cancer and compare the US classification of risk of LN metastasis between European and Korean guidelines. Materials and Methods: From January 2014 to December 2018, US-guided fine-needle aspiration was performed on 836 LNs from 714 patients for the preoperative nodal staging of thyroid cancer. The US features of LNs were retrospectively reviewed for the following features: size, presence of hilum, margin, orientation, cystic change, punctate echogenic foci (PEF), large echogenic foci, eccentric cortical thickening, abnormal vascularity, and cortical hyperechogenicity. A multiple logistic regression analysis was performed to identify the independent US features for the diagnosis of metastatic LNs. The diagnostic performance of independent US features was subsequently evaluated. LNs were categorized according to the Korean Thyroid Imaging Reporting and Data System (K-TIRADS) and European Thyroid Association (ETA) guidelines, and the correlation between the two sets of classifications was assessed. Results: Absence of the hilum, presence of cystic changes, PEF, abnormal vascularity, and cortical hyperechogenicity were independent US features of metastatic LNs. Cystic changes, PEF, abnormal vascularity, and cortical hyperechogenicity showed high specificity (86.8%-99.6%). The absence of the hilum had the highest sensitivity yet low specificity (66.4%). When LNs were classified according to the ETA guidelines and K-TIRADS, they yielded similar categorizations of malignancy risks and were strongly correlated (Spearman coefficient, 0.9766 [95% confidence interval, 0.973-0.979]). According to the ETA guidelines, 9.8% (82/836) of LNs were classified as "not specified." Conclusion: Absence of hilum, cystic changes, PEF, abnormal vascularity, and cortical hyperechogenicity were independent US features suggestive of metastatic LNs in thyroid cancer. Both K-TIRADS and the ETA guidelines provided similar risk stratification for metastatic LNs with a high correlation; however, the ETA guidelines failed to classify 9.8% of LNs into a specific risk stratum. These results may provide a basis for revising LN classification in future guidelines.

• Proceedings of the KSMRM Conference
• /
• 2001.11a
• /
• pp.108-108
• /
• 2001

Purpose： To correlate the histological differentiation of hepatocellular carcinomas (HCCs) with finding on triple contrast-enhanced MR imaging using gadolinium-chelates, superparamganetic ire oxides (SPIO), and mangafodipir trisodium. Method： Ten patients with proven HCC underwent triple contrast-enhanced MRI befo surgical resection. Subjective ratings of the enhancement pattern and degree were compare with the histological grades determined on surgical specimen. Quantitative measurements signal-to-noise ratio (S/N) of the lesion and the lesion-to-liver contrast-to-noise ratio C/N on the enhanced MR images, and the degree of S/N and C/N changes between the unenhanced and enhanced images were also correlated with the histological grades.

• Investigative Magnetic Resonance Imaging
• /
• v.11 no.1
• /
• pp.27-32
• /
• 2007

Purpose : To evaluate the mucoid degeneration (MD) of the anterior cruciate ligament (ACL) of the knee by correlation of MRI findings with pathology, in the patients with osteoarthritis (OA). Materials and Methods : This study included 17 patients (mean 68.8 years old) who underwent preoperative MRI. In proton density-weighted sagittal and coronal images ACLs were evaluated for the thickness and signal intensity (SI). Total knee replacement arthroplasty was performed and the pathologic findings of ACL were evaluated. MD was classified as 3 grades according to the degenerated amount in microscopy. Thickness and SI was evaluated as normal or increased on MRI. Results : All of the 4 patients who showed thickened ACL showed increased SI on MRI. All of the 8 patients with increased SI of the ACL on MRI had MD in the ACL. However, remained 9 patients also had MD, in spite of their normal thickness and SI on MRI. Calcification was seen in 5 patients. Conclusion : Eight cases who showed ACL thickening or increased SI on MRI were well correlated with MD, however, because the other nine cases who showed normal thickness and normal SI of ACL on MRI also showed MD in pathology, normal MRI finding should not exclude the possibility of MD of ACL.