Seon Kwan Juhng

Colloidal gold nanoparticles as a blood-pool contrast agent for X-ray computed tomography in mice.

Objectives:To present the pharmacokinetics and computed tomographic imaging efficacy of colloidal gold nanoparticles (AuNPs) as a blood-pool agent for x-ray computed tomography (CT). Methods and Materials:To prepare the colloidal AuNPs, gold nanocrystals were modified using sulfhydrated polyethylene glycol (PEG). Cytotoxicity and histopathologic tests were carried out for toxicity evaluation. Six adult Balb/c mice underwent microcomputed tomography scans after injection of colloidal AuNPs (2.5 &mgr;mol Au/g body weight). Four mice with HT-1080 tumors were imaged for visualization of the tumor vasculature. Results:The PEG coated colloidal AuNPs appeared as spherical nanoparticles with 38-nm diameters. The AuNPs-PEG showed a biocompatibility without toxicity in the mice. We identified a stable imaging window for visualizing the vasculature system, immediately to 24 hours after injection. Microcomputed tomography imaging using AuNPs-PEG clearly visualized the tumor vascular structures. Conclusion:Colloidal AuNPs show potential as a blood-pool agent for x-ray CT imaging.

Mucoepidermoid Carcinoma of the Thymus: A Case Report

Mucoepidermoid carcinoma of the thymus is an extremely rare malignant mediastinal neoplasm, and to our knowledge, only 13 cases have been reported. We report a case of mucoepidermoid carcinoma of the thymus that was seen in a 53-yr-old man with right chest pain. Chest CT scan showed a huge, cystic mass having a focal solid portion with direct invasion of the adjacent anterior chest wall and pericardium in the anterior mediastinum. Mucoepidermoid carcinoma of the thymus should be included in the differential diagnosis for masses of the anterior mediastinum associated with extensive cystic changes, although the carcinoma is exceedingly rare.

Focal hepatic lesions: contrast-enhancement patterns at pulse-inversion harmonic US using a microbubble contrast agent.

Objective To analyze the contrast-enhancement patterns obtained at pulse-inversion harmonic imaging (PIHI) of focal hepatic lesions, and to thus determine tumor vascularity and the acoustic emission effect. Materials and Methods We reviewed pulse-inversion images in 90 consecutive patients with focal hepatic lesions, namely hepatocellular carcinoma (HCC) (n=43), metastases (n=30), and hemangioma (n=17). Vascular and delayed phase images were obtained immediately and five minutes following the injection of a microbubble contrast agent. Tumoral vascularity at vascular phase imaging and the acoustic emission effect at delayed phase imaging were each classified as one of four patterns. Results Vascular phase images depicted internal vessels in 93% of HCCs, marginal vessels in 83% of metastases, and peripheral nodular enhancement in 71% of hemangiomas. Delayed phase images showed inhomogeneous enhancement in 86% of HCCs; hypoechoic, decreased enhancement in 93% of metastases; and hypoechoic and reversed echogenicity in 65% of hemangiomas. Vascular and delayed phase enhancement patterns were associated with a specificity of 91% or greater, and 92% or greater, respectively, and with positive predictive values of 71% or greater, and 85% or greater, respectively. Conclusion Contrast-enhancement patterns depicting tumoral vascularity and the acoustic emission effect at PIHI can help differentiate focal hepatic lesions.

CT imaging biomarker for evaluation of emodin as a potential drug on LPS-mediated osteoporosis mice.

RATIONALE AND OBJECTIVES To identify micro-computed tomography (CT) imaging biomarkers for evaluating the effects of emodin, a potential drug to treat osteoporosis, in the mouse model of lipopolysaccharide (LPS)-mediated osteoporosis. MATERIALS AND METHODS Forty male imprinting control region (ICR) mice with LPS-induced bone resorption were equally divided into four experimental groups: phosphate-buffered saline-treated (control), emodin-treated, LPS-treated, and LPS + emodin-treated groups. Emodin (50 mg/kg) was administered orally on alternate days for 8 days, and LPS (5 mg/kg) was injected intraperitoneally on days 1 and 4. After 8 days, the mice were sacrificed, and micro-CT images of the left proximal femurs were obtained. Three-dimensional images were analyzed by using commercial software to measure the bone volume to total volume fraction (BV/TV), trabecular number (Tb-N), trabecular thickness (Tb-Th), and trabecular separation (Tb-Sp) as CT imaging biomarkers. Histologic analyses of the femurs were performed using hematoxylin and eosin and tartrate-resistant acid phosphatase (TRAP) immunohistochemical staining. RESULTS The LPS + emodin-treated group demonstrated marked suppression of LPS-induced bone resorption compared to the LPS-treated group (BV/TV, 28.84% vs. 40.76%; Tb-N, 2.65 vs. 3.45 mm(-1); Tb-Sp, 300.81 vs. 212.31 μm; Tb-Th, 116.94 vs. 131.25 μm). TRAP immunohistochemical analysis showed fewer osteoclasts per field of tissue in the LPS + emodin-treated group than in the LPS-treated group (27.8 vs. 41.8). The BV/TV, Tb-N, and Tb-Sp data correlated well with the histomorphometric findings. CONCLUSIONS The findings reveal a novel effect of emodin on bone remodeling in the LPS-mediated osteoporotic mouse model. The ex vivo micro-CT imaging is a promising tool for assessing the therapeutic effects of potential drugs on osteoporosis.

Imaging Findings Of Desmoplastic Fibroma Rarely Involving The Clavicle: Case Report

Desmoplastic fibroma of bone is a rare locally aggressive, but non-metastatic tumor. In this case report, we present a desmoplastic fibroma in an unusual location, the clavicle. Desmoplastic fibroma involving the clavicle is extremely rare, with only 2 reported cases before 1985. We report the imaging findings of a desmoplastic fibroma of the clavicle with a review of the relevant literature.

Micro‐CT measurements of tumoral vessels supplied by portal circulation in hepatic colorectal metastasis mouse model

The purpose of this study was to elucidate the micro CT findings of tumoral vessels supplied by portal circulation during establishment of hepatic metastasis of colorectal cancer in a mouse model. Hepatic metastases were induced in 15 BALB/c mice through the injection of murine colonic adenocarcinoma tumor cells into the mesenteric vein. Micro‐CT imaging of the tumoral vessels was obtained to clarify the microvascular architecture. We evaluated the sinusoidal structure, diameter of the tumoral vessels (DTV) and blood vessel density (BVD) according to tumor sizes ranging from 201 to 3,000 µm in diameter. A total of 116 tumors were observed on day 15 after cell injection. The mean diameter of a normal hepatic sinusoid was 11.7 ± 2.0 µm on micro CT. The DTV supplied by the portal vein of tumors measuring 1,001–1,500 µm in diameter was greater than that of tumors 200–1,000 µm in diameter. The mean BVD from the portal vein gradually decrease according to size of tumor from 201 to 3,000 µm in diameter (r2 = −0.584, P < 0.01). The characteristics of tumoral vessels supplied by portal circulation during establishment of hepatic colorectal metastases were well visualized with micro‐CT imaging. Microsc. Res. Tech. 77:415–421, 2014.

Superior Mediastinal Widening from Traumatic Posterior Dislocation of Sternoclavicular Joint: A Case Report

Superior mediastinal widening, as seen on chest radiographs of traumatized patients, has been considered the hallmark of mediastinal injury. The usual causes of superior mediastinal widening are rupture of the aorta, esophagus or trachea, and hematoma as a result of spinal fracture. Posterior dislocation of the sternoclavicular joint is rarely a cause. We report a case of superior mediastinal widening resulting from traumatic posterior dislocation of the stern-oclavicular joint, and describe the CT findings, including those of 3-D imaging.

CT of mediastinal hemangioma: case report

AbstractWe decribe the CT findings in a case of mediastinal hemangioma. Precontrast enhanced CT demonstrated a homogeneous soft tissue mass with several nodular calcifications indicating phleboliths. Contrast enhanced CT revealed some areas of enhancement similar to that of adjacent vascular structures. Hemangiomas of the mediastinum, although rare, should be included in the differential diagnosis of enhancing mediastinal masses