Jeong Soo Suh

Halo sign on high resolution CT: findings in spectrum of pulmonary diseases with pathologic correlation.

The halo sign in a pulmonary nodule refers to the condition in which soft tissue attenuation of a pulmonary nodule is surrounded by peripheral ground glass attenuation on high resolution CT. The halo sign can be caused by several pathologic processes: hemorrhagic pulmonary nodules, tumor cell infiltration, and nonhemorrhagic inflammatory lesions. Hemorrhagic pulmonary nodules may occur in infectious diseases including invasive pulmonary aspergillosis, mucormycosis, and candidiasis and noninfectious diseases including Wegener granulomatosis and primary and metastatic hemorrhagic tumors. Tumor cell infiltration in bronchioloalveolar carcinoma, pulmonary lymphoma, and pulmonary metastatic neoplasm may appear with the halo sign. Eosinophilic lung disease and organizing pneumonia are representative of inflammatory lesions showing the sign.

Sonographic findings in a model of ischemia-induced necrotizing enterocolitis with pathological correlations.

Purpose:To evaluate sonographic findings in ischemic enterocolitis (IEC) and correlate with pathologic findings in an experimental study. Materials and Methods:Ischemic enterocolitis was induced with ligation of the superior mesenteric artery in 20 rabbits. Plain radiography and ultrasonography (US) were performed. US was done hourly after the ligation using 10 MHz linear probe. US findings were categorized into 2 groups according to the bowel wall echogenicity; the echogenic dots (ED) group and the circumferential granular echogenicity (CGE) group. US findings were compared with the specimen radiography and the histopathology. Results:On US, ED were seen in the bowel of all rabbits after SMA ligation (2.2 ± 1.3 hours [standard deviation]) and CGE in 16 rabbits (4.1 ± 0.9 hours). On the specimen radiographs, multiple radiolucent air bubbles were present. Comparing the ED and CGE group, histopathological findings revealed the CGE group had severer injury of the bowel wall than the ED group. On plain radiography, there was progressive bowel distention, but pneumatosis intestinalis (PI) was not evident. Conclusion:ED or CGE are the sonographic findings of ischemic enterocolitis, and bowel wall echogenicity might reflect the degree of ischemic injury.

Leiomyoma of the bronchus treated by endoscopic resection

Leiomyoma of the bronchus is a rare benign tumor. The type of surgical resection depends on the location of the tumor and secondary lung destruction, although most surgical treatment has required thoracotomy. Two Korean women who had pedunculated masses in the left main bronchus and in the right lower lobe bronchus were successfully treated by endoscopic resection. Their postoperative courses were uneventful. They are well 19 months and 10 months, respectively, after resection.

Magnetic resonance imaging of bowel ischemia induced by ligation of superior mesenteric artery and vein in a cat model

Objective: To assess the usefulness of magnetic resonance (MR) imaging for detecting bowel ischemia with strangulation compared with histopathologic findings in an experimental cat model. Materials and Methods: Fourteen cats were assigned to the normal control group (n = 3), acute ischemic group (induced by ligation of superior mesenteric vessels for 3 hours, n = 7), and subacute ischemic group (induced by ligation of superior mesenteric vessels for 10 hours, n = 4). Using a 4.7-T MR scanner, contrast-enhanced T1-weighted images were obtained at 0, 10, 20, 30, and 60 minutes after bolus injection of contrast media. T1- and T2-weighted images were obtained from the extracted bowel wall and compared with histopathologic findings. Results: On contrast-enhanced MR images, the target-like bowel wall layers were clearly demonstrated and the submucosal layer showed the most prominent enhancement. At 10 minutes after administration of contrast media, the subacute ischemic group showed significantly lower enhancement of the submucosal layer than the normal or acute ischemic group (P <0.05). On T1-weighted images, there were not significant differences between the normal and ischemic bowel groups (P >0.05). On T2-weighted images, the signal intensity of all layers of acute ischemic bowel wall was significantly higher than that of the normal control or subacute ischemic group (P <0.05). Conclusion: Delayed contrast-enhanced MR images and T2-weighted images were helpful for detecting subacute and acute bowel ischemia with strangulation, respectively.

Melanotic paraganglioma arising in the temporal horn following Langerhans cell histiocytosis

Intracerebral paragangliomas are rare because of the lack of paraganglial cells in the cerebral tissue. We report a rare case of melanotic paraganglioma arising from the temporal horn of the lateral ventricle in a patient with prior Langerhans cell histiocytosis (LCH) treated with chemotherapy and radiation.