Yeon Soo Lim

Emphasis on the MR imaging findings of brown tumor: a report of five cases

ObjectiveBrown tumors are focal reactive osteolytic lesions that are encountered in patients with primary or secondary hyperparathyroidism, and these tumors have nonspecific magnetic resonance (MR) imaging findings. However, there are only a few reports on MR imaging of brown tumors. The purpose of this study is to describe the spectrum of MR imaging findings of brown tumors.Materials and methodsThe MR imaging features of five patients with clinical and pathological evidence of brown tumor were retrospectively reviewed by two radiologists. The patients had primary hyperparathyroidism, which was confirmed as parathyroid adenoma (n = 2) and parathyroid carcinoma (n = 3). The MR images were evaluated for the presence of solid or cystic portions, the signal intensity of the lesions, the contrast enhancement pattern and the presence of cortex destruction and fluid-fluid levels.ResultsTwelve bone lesions were detected on the MR images of five patients; three lesions in two patients, four lesions in one patient, and one lesion in two patients. The tumor was solid in three lesions, mixed solid and cystic in four, and cystic in five. All the solid lesions were accompanied by mixed lesions. Discontinuity of the cortex and adjacent soft-tissue enhancement were seen in all the solid lesions. Fluid-fluid levels were seen in two cases within the cystic component of the mixed lesions and cystic lesions.ConclusionsThe five patients with brown tumor demonstrated a wide spectrum of MR imaging findings. There are few lesions that are osteolytic on the radiographs and that show a short T2 on MR imaging, such as brown tumor. Multiple cystic or mixed lesions are the expected findings of brown tumors.

Cytotoxicity of yellow sand in lung epithelial cells

The present study was carried out to observe the cytotoxicity of yellow sand in comparison with silica and titanium dioxide in a rat alveolar type II cell line (RLE-6TN). Yellow sand (China Loess) was obtained from the loess layer in the Gunsu Province of China. The mean particle diameter of yellow sand was about 0003 ± 0.001 mm. Major elements of yellow sand were Si(27.7 ± 0.6%), Al(6.01± 0.17%), and Ca(5.83 ± 0.23%) in that order. Silica and yellow sand significantly decreased cell viability and increased [Ca2+]i. All three particles increased the generation of H2O2. TiO2 did not change Fenton activity, while silica induced a slight increase of Fenton activity. In contrast, yellow sand induced a significant increase of Fenton activity. Silica, yellow sand and TiO2 induced significant nitrite formations in RLE-6TN cells. Silica showed the highest increase in nitrite formation, while yellow sand induced the least formation of nitrite. Silica and yellow sand increased the release of TNF-α. Based on these results, we suggest that yellow sand can induce cytotoxicity in RLE-6TN cells and reactive oxygen species, Fenton activity and reactive nitrogen species might be involved in this toxicity.

Role of magnetic resonance cholangiopancreatography for choledocholithiasis: Analysis of patients with negative MRCP

Abstract Objective. To investigate the negative predictive value of magnetic resonance cholangiopancreatography (MRCP) for common bile duct (CBD) stones and the prognosis of patients suspected to have choledocholithiasis in whom the MRCP was negative for CBD stones. Methods. We enrolled the patients suspected to have choledocholithiasis in whom the MRCP was negative for the CBD stones between January 2008 and March 2011 and retrospectively analyzed the outcomes of 115 patients. Results. Endoscopic retrograde cholangiopancreatography (ERCP) was performed in 27 patients (23%, group 1), and none had CBD stones. The negative predictive value of MRCP was 100%. During a median follow-up of 18.3 months, acute cholangitis with newly developed CBD stones occurred in two patients. Eighty-eight patients (77%, group 2) did not undergo ERCP and all recovered from acute cholangitis without CBD surgery. During a median follow-up of 18.7 months, acute cholangitis, acute cholecystitis, gallstone pancreatitis, and pancreatico-biliary cancers occurred in four (4.6%), three (3.5%), one (1.2%), and three (3.5%) patients, respectively. New CBD stones were found in only two patients among four patients with recurrent acute cholangitis. No patient had recurrent cholangitis caused by MRCP-missed CBD stones. The rates of recurrent cholangitis and cholangitis-free survival did not differ between groups 1 and 2. Conclusion. The negative predictive value of MRCP was very high. ERCP can be reserved for patients who are MRCP negative for choledocholithiasis, but close follow-up is needed because of recurrent cholangitis or pancreatico-biliary cancer.

Polyvinyl alcohol embolization adjuvant to oily chemoembolization in advanced hepatocellular carcinoma with arterioportal shunts.

Objective To assess the feasibility and safety of polyvinyl alcohol (PVA) embolization adjuvant to transarterial oily chemoembolization (P-TACE) in advanced hepatocellular carcinoma (HCC) with arterioportal shunts (APS). Materials and Methods Nineteen patients who underwent PVA embolization for APS before a routine chemoembolization (TACE) procedure were retrospectively reviewed. 10 of these 19 patients underwent follow-up TACE or P-TACE after P-TACE (Group A), but nine patients underwent only initial P-TACE because of progression of HCC and/or underlying liver cirrhosis (Group B). Hepatic function tests, APS grades, and portal flow directions were evaluated before and after P-TACE sessions. Complications after procedures and survival days were also evaluated. Results In group A, APS grade was improved in eight patients and five of six patients with hepatofugal flow showed restored hepatopetal flow postoperatively. No immediate complication was developed in either group. Transient hepatic insufficiency developed in eight (42.1%) of 19 patients after P-TACE, and seven (87.5%) of these eight recovered within two weeks under conservative care. The mean and median survival time all study subjects was 280 days and 162 days. Conclusion P-TACE is feasible and safe in advanced HCC patients with APS.

Utility of the resistance index ratio in differentiating obstructive from nonobstructive hydronephrosis in children

We assessed the utility of the resistance index ratio (RIR) in distinguishing between obstructive and nonobstructive upper urinary tract dilatation in children.

Interleukin-6 is associated with obesity, central fat distribution, and disease severity in patients with acute pancreatitis

BACKGROUND/OBJECTIVE Acute pancreatitis (AP) is a systemic inflammatory disease, and cytokines are suggested to be related to the course of AP. Obesity and central fat distribution are considered to have been associated with severe AP. This study investigated the profile of inflammatory cytokines in AP to determine how they are related to obesity, central fat distribution, and AP severity. METHODS Fifty-nine patients with AP were prospectively enrolled in the study. Body mass index and waist circumference were obtained at admission. Serum levels of inflammatory cytokines, IL-Iβ, IL-1ra, IL-6, TNF-α, sTNFR-I, and sTNFR-II, were measured on day 1 and 2 of AP. RESULTS Of the patients included in the study, 19 (32%) were overweight, 23 (39%) had central fat distribution, and 23 (39%) had moderate AP. IL-1ra and IL-6 were significantly higher in overweight patients compared with non-overweight patients. IL-1ra, IL-6, TNF-α, and sTNFR-I were significantly higher in patients with central fat distribution compared with patients with non-central fat distribution. IL-6, sTNFR-I, and sTNFR-II were significantly higher in patients with moderate pancreatitis compared to those with mild pancreatitis. Among the six cytokines, IL-6 was commonly elevated in patients with central fat distribution, overweight, and moderate AP. The areas under the receiver operating characteristic curves of IL-6 for predicting the association with overweight, central fat distribution, and AP severity were 0.678, 0.716, and 0.801, respectively (P < 0.05). CONCLUSIONS IL-6 is a good marker for AP severity and is associated with obesity and central fat distribution in AP patients.

Common bile duct stones on multidetector computed tomography: Attenuation patterns and detectability

AIM To investigate the attenuation patterns and detectability of common bile duct (CBD) stones by multidetector computed tomography (MDCT). METHODS Between March 2010 and February 2012, 191 patients with suspicion of CBD stones undergoing both MDCT and endoscopic retrograde cholangiopancreatography (ERCP) were enrolled and reviewed retrospectively. The attenuation patterns of CBD stones on MDCT were classified as heavily calcified, radiopaque, less radiopaque, or undetectable. The association between the attenuation patterns of CBD stones on MDCT and stone type consisting of pure cholesterol, mixed cholesterol, brown pigment, and black pigment and the factors related to the detectability of CBD stones by MDCT were evaluated. RESULTS MDCT showed CBD stones in 111 of 130 patients in whom the CBD stones were demonstrated by ERCP with 85.4% sensitivity. The attenuation patterns of CBD stones on MDCT were heavily calcified 34 (26%), radiopaque 31 (24%), less radiopaque 46 (35%), and undetectable 19 (15%). The radiopacity of CBD stones differed significantly according to stone type (P < 0.001). From the receiver operating characteristic curve, stone size was useful for the determination of CBD stone by MDCT (area under curve 0.779, P < 0.001) and appropriate cut-off stone size on MDCT was 5 mm. The factors related to detectability of CBD stones on MDCT were age, stone type, and stone size on multivariate analysis (P < 0.05). CONCLUSION The radiopacity of CBD stones on MDCT differed according to stone type. Stone type and stone size were related to the detectability by MDCT, and appropriate cut-off stone size was 5 mm.

Relationship of visceral and subcutaneous adiposity with renal function in people with type 2 diabetes mellitus

BACKGROUND Obesity and diabetes mellitus (DM) are established risk factors for the development of chronic kidney disease. Visceral adiposity (VAT) and subcutaneous adiposity (SAT) may be associated with the differential metabolic risk. Our study was performed to determine whether VAT or SAT was associated with the decrease of renal function in people with type 2 DM. METHODS Nine hundred and twenty-nine people with type 2 DM and who had undergone abdominal computed tomography assessment of the SAT and VAT areas were included. The estimated glomerular filtration rate (eGFR) was calculated using the Cockcroft-Gault equation and the Modification of Diet in Renal Disease (MDRD) four-variable equation at the time of the assessment of the SAT and VAT areas. RESULTS VAT was negatively associated with eGFR using the MDRD equation after adjustment for the clinical variables (β-coefficient = - 0.075, P = 0.034), while SAT was not significantly associated with eGFR. There was no significant association between the abdominal adiposity measurements and the eGFR using the Cockcroft-Gault formula. When stratifying the individuals by the body mass index groups, VAT was negatively associated with eGFR by the MDRD equation and the Cockcroft-Gault formula in the overweight and obese subjects after adjustment for the clinical variables, while there was no significant association between the VAT and the eGFR in the normal weight subjects. SAT was not significantly associated with eGFR in the normal weight, overweight and obese subjects. CONCLUSIONS Our data suggest that VAT may be an additional prognostic factor for the decrease of renal function especially in the overweight or obese subjects with type 2 DM.

Evaluation of middle cerebral artery stents using multidetector row CT angiography in vivo study: comparison of the three different kernels

Background There are very few reports assessing middle cerebral artery (MCA) stents using multidetector computed tomography (MDCT). Purpose To assess MCA stents using multidetector CT angiography (CTA) in vivo evaluation: the differences in the CTA results according to the three different kernels. Material and Methods We retrospectively evaluated 27 MCA stents from 26 patients who underwent CTA with 16- and 64-slice MDCT after percutaneous transluminal angioplasty and stenting (PTAS). By CTA, using medium-smooth kernel (B30), medium-sharp kernel (B50), and sharp kernel (B60), the lumen diameter, artificial luminal narrowing (ALN), and subjective visibility score of the stented vessels were evaluated. The subjective visibility score ranged from 1 (poor quality) to 5 (excellent) using a five-point scale. Results There were excellent inter-observer agreements for the lumen diameter measurements (P < 0.001). The mean diameter of the stented vessels was 2.10 ± 0.31 mm on digital subtraction angiography (DSA), 0.93 ± 0.20 mm on CTA using B30, 1.18 ± 0.27 mm on CTA using B50, and 1.29 ± 0.29 mm on CTA using B60. The mean ALN was 55.7 ± 6.0% on CTA using B30, 43.8 ±7.5% on CTA using B50, and 38.7 ± 8.3% on CTA using B60. CTA with higher kernels had a smaller ALN than images with smaller kernels. The median subjective visibility score on the CTA using B50 was 3, which was higher than for the other kernels. The differences in the lumen diameter, ALN, and the subjective visibility score of the stented vessels on CTA using the three different kernels was statistically significant (P < 0.001). Conclusion The sharp kernel was better to assess the lumen diameter and ALN, but was inferior to the medium-sharp kernel for in-stent evaluation due to high image-to-noise. CTA with medium-sharp kernel showed good lumen visibility and acceptable ALN for MCA stents. This could therefore be a non-invasive, readily applicable clinical method for assessing MCA stent patency after stent placement.

Giant cell tumor with secondary aneurysmal bone cyst: A unique presentation with an ossified extraosseous soft tissue mass

The authors describe a case of giant cell tumor (GCT) with secondary aneurysmal bone cyst (ABC) in a 44-year-old man with chronic, intermittent knee pain. A unique feature is the presentation of GCT with an ossified extraosseous soft tissue mass. Radiograph demonstrates a multiloculated lytic lesion in the distal meta-epiphyseal region of the femur with an adjacent extraosseous soft tissue mass. The soft tissue mass was partially ossified along its margin and internal septa. MRI demonstrates a multiloculated lesion in the distal femur with multiple fluid–fluid levels and cortical penetration of the lesion. Both the intraosseous lesion and extraosseous soft tissue mass have similar MR signal characteristics. At surgery, the intraosseous component was found to be contiguous with the extraosseous soft tissue mass through a cortical perforation. To the best of our knowledge, this is the first case report of GCT with aneurysmal bone cyst initially presenting with an extraosseous soft tissue mass.