[en] Highlights: • A thermal conductance switch based on electrowetting is proposed. • Theoretical models for switching operation are developed and experimentally validated. • The thermal performance of the thermal switches is characterized experimentally. • Numerical simulation suggests heat transfer enhancement by thermocapillary flows. - Abstract: Thermal conductance switches enable active and reconfigurable thermal control and management for a wide variety of applications. We demonstrate a thermal conductance switch based on the actuation of liquid droplets in a co-planar electro-wetting-on-dielectric (EWOD) configuration. By eliminating the need for relative motions of two heat transfer surfaces, the device provides a significant advantage in the mechanical design of adaptive thermal control systems. Proof-of-concept devices are constructed and characterized to confirm the mechanism of droplet detachment and attachment for thermal switching. Numerical simulation is performed to elucidate the experimentally measured thermal performance and identify thermocapillary flows as an important contributor to heat transfer for certain dielectric liquids. The present work provides a proof-of-concept demonstration of novel thermal conductance switches and offers physical insights to help systematically design the switches for practical applications.

[en] A broad spectrum of colonic complications can occur in patients with colon cancer. Clinically, some of these complications can obscure the presence of underlying malignancies in the colon and these complications may require emergency surgical management. The complications of the colon that can be associated with colon cancer include obstruction, perforation, abscess formation, acute appendicitis, ischemic colitis and intussusception. Although the majority of these complications only rarely occur, familiarity with the various manifestations of colon cancer complications will facilitate making an accurate diagnosis and administering prompt management in these situations. The purpose of this pictorial essay is to review the CT appearance of the colonic complications associated with colon cancer

[en] Cysts overlying the temporal lobes have been well described in literature. These are often associated with agenesis of the temporal lobes, and of major neurosurgical interest due to their frequent association with subdural hematoma, a combination that is rarely seen with cysts in other regions. Full features of plain, angiographic, and CT findings of arachnoid cyst with temporal lobe agenesis accompanying isodense subdural hematoma are presented, being very rare in radiologic literature

[en] The Meckel's cave is a dural recess containing trigeminal nerve and ganglion, extending from the posterior fossa into the middle cranial fossa. Using MRI, internal architecture in the Meckel's cave can be discernible, even a small nodule within it can be detected. There are a wide spectrum of disease process occurring in and or in the vicinity of the Meckel's cave. Disease can be classified into pathology of the trigeminal nerve proper, within the trigeminal cistern and outside the trigeminmal cistern. These classification depending on the location will aid in interpretation of pathology of Meckel's cave. We will demonstrate the MR anatomy and various pathologies of the Meckel's cave.=20

[en] The purpose of this study is to describe the characteristic MRI findings of the Rathke cleft cyst. During a seven-year period, we retrospectively evaluated the MRI findings of 24 pathologically-proven Rathke cleft cysts. The patients included ten men and 14 women, and their mean age was 37. MRI findings were analyzed in terms of location, shape, size, signal intensity, homogeneity of cyst content, pattern of contrast enhancement, displacement of the pituitary stalk, and mass effect of the cyst on adjacent structures. MRI findings of midline intrasellar cyst with a staging water bag appearance, high signal intensity on T1- and T2WI, inhomogeneity of cyst content, and peripheral rim enhancement surrounding the cyst are common, and are characteristic of the Rathke cleft cyst. (author). 23 refs., 5 figs

[en] A lymphoepithelioma-like carcinoma, characterized by a carcinoma with heavy lymphocyte infiltration, is one of the histological patterns observed in patients with Epstein-Barr virus (EBV)-associated gastric carcinoma. Less than half of invasive carcinomas with lymphoepithelioma-like histology can grow to make a submucosal mass. These tumors generally have a better prognosis than conventional adenocarcinomas. We report a case of an EBV-associated lymphoepitheliomalike gastric carcinoma that presented as a submucosal mass on multi-detector (MD) CT and correlate them with the pathology

[en] We reviewed the radiologic, physiologic, and pathologic features of biopsy-proved pulmonary lymphangioleiomyomatosis (LAM) in 2 patients. Chest radiographs showed diffuse increased interstitial lung markings with normal or slightly increased lung volume. The prominent computed tomographic (CT) feature was thin-walled cysts throughout the lungs. Pulmonary function test showed a mixed obstructive and restrictive pattern in one and a mainly restrictive pattern in another, which was somewhat different from that of the reported cases. Proliferation of smooth muscle cells in the lymphatics, alveolar septae, vessels, and bronchioles was the pathologic finding

[en] The apex of the orbit is basically formed by the optic canal, the superior orbital fissure, and their contents. Space-occupying lesions in this area can result in clinical deficits caused by compression of the optic nerve or extraocular muscles. Even vascular changes in the cavernous sinus can produce a direct mass effect and affect the orbit apex. When pathologic changes in this region is suspected, contrast-enhanced MR imaging with fat saturation is very useful. According to the anatomic regions from which the lesions arise, they can be classified as belonging to one of five groups; lesions of the optic nerve-sheath complex, of the conal and intraconal spaces, of the extraconal space and bony orbit, of the cavernous sinus or diffuse. The characteristic MR findings of various orbital lesions will be described in this paper. (author)

[en] We retrospectively reviewed magnetic resonance image findings of the primary CNS lymphomas in six patients. All patients showed parenchymal masses (n=8), a solitary mass in 4 and multiple in the other two. One patients showed leptomeningeal lesions. Parenchymal masses were located in forntal lobe (n=4), cerebellum (n=2), basal ganglia (n=1), and parietal lobe (n=1). There masses showed hypointensity on T1-weighted images (WI). On T2 WI, the signal intensity of mass was isointense to the brain parenchyma in 5 and hyperintense in 3. After Gadolinium-DTPA injection, seven lesions were enhanced homogeneously, and the margin of the mass was smooth in 5 and irregular in 3. Peritumoral edema was moderate in 4, absent in 3, and severe in 1. These characteristics may be useful in the diagnosis of primary CNS lymphoma

[en] With regard to various pathologic conditions, it is important to understand not only MR findings, which depend on the anatomic location of intraventricular lesions, but also the anatomic location most appropriate for surgical intervention. In this paper we will analyze and demonstrate the incidence and characteristic MR findings of various intraventricular tumors according to the location of ventricles. (author). 6 refs., 1 tab., 11 figs