فهرست مطالب cheol min park

Radiofrequency ablation (RFA) is not feasible when hepatocellular carcinoma (HCC) is poorly defined or invisible on conventional gray-scale ultrasonography (GSUS). Recent introduction of contrast-enhanced ultrasonography (CEUS) helps diagnose HCC by showing its typical enhancement pattern.
The purpose of this study is to demonstrate the added value of CEUS as a RFA planning modality for HCC compared with conventional GSUS.
Patients and A total of 64 HCCs from 57 patients (men:women = 41:16; mean age, 62.6) who had undergone GSUS and CEUS for RFA planning in 2011 were retrospectively reviewed. Ultrasound contrast agent was used for CEUS after conventional GSUS. The recorded images of GSUS and CEUS were reviewed retrospectively. On GSUS, the size, location, echogenicity, and margin of each HCC were reviewed. The visibility scores of HCC on GSUS and CEUS were measured using a 3-point scale. GSUS visibility score: score 1, definite nodule with well-defined margin; score 2, slightly hypo-/hyperechoic nodule with partial margin; score 3, isoechoic nodule without margin. CEUS visibility score: score 1, arterial enhancement; score 2, only delay washout; score 3, no arterial enhancement or washout.
The mean size of HCCs was 1.8 cm (range, 1.0 - 4.8 cm). Among 64 HCCs, visibility score 1 were 37; score 2, 8; score 3, 19 on GSUS. By performing CEUS, 10 out of 19 HCCs with GSUS visibility score 3 showed CEUS visibility score 1. Seven out of 8 HCCs with GSUS visibility score 2 showed CEUS visibility score 1. Total 37 HCCs showed visibility score 1 on GSUS; whereas, 53 HCCs showed visibility score 1 on CEUS (57.8% vs. 82.8%).
CEUS can be an effective RFA planning modality when a target HCC is invisible or questionable on GSUS.

Neuroendocrine carcinomas (NECs) of the stomach are poorly differentiated, high-grade endocrine tumors, including small cell and large cell carcinomas. They are deeply invasive and metastatic, with a poor prognosis. The purpose of this study is to describe the computed tomography (CT) findings of gastric NECs with pathologic features.
Patients and CT examinations of 32 patients with gastric NECs from January 2004 to January 2015 were reviewed retrospectively for tumor morphology, size, and CT attenuation. CT attenuation of the lymph nodes, peritumoral infiltration, and associated findings, such as liver metastasis and peritoneal carcinomatosis were also reviewed. The ages of patients ranged from 45 to 79 years (mean: 62 years). Twenty-seven patients (84%) were men. Pathologic diagnosis was made using gastrectomy (n = 28) and endoscopic biopsy (n = 4). Nineteen patients underwent multidetector CT with water as an oral contrast agent, and 13 patients underwent helical CT with water.
Among the three CT morphologic types of gastric NEC (polypoid, ulcerofungating, and ulceroinfiltrative), 63% of those in our study were ulcerofungating (n = 20), 37% were ulceroinfiltrative, and none were polypoid. All were larger than 5 cm in the greatest diameter (mean size: 7.8 cm). The characteristic features at presentation were focal (n = 3) or diffuse (n = 15) low attenuation within the mass, extensive low attenuation lymphadenopathy (n = 13), and liver metastasis (n = 6). There were no significant differences between the small cell (n = 10) and the large cell NEC groups (n = 22).
Although differential diagnosis between gastric adenocarcinoma and gastric NEC is difficult, gastric NEC should be considered when CT shows a large ulcerofungating tumor with low attenuation areas (pathologically mucinous or necrotic), especially combined with extensive necrotic lymphadenopathy and frequent hepatic metastases.

Ureteral stent exchange is usually performed under both fluoroscopic and cystoscopic guidance. We experienced two cases with retrograde placement of metallic ureteral stent via urethra under fluoroscopic guidance. When patients with double-J ureteral stent (DJUS)have symptom and want to change DJUS to metallic stent, fluoroscopic guided transurethral placement of ureteral metallic stent is a good option as alternative of cystoscopic procedure or percutaneous procedure through percutaneous nephrostomy tract.