Eccentric Wall Research Articles

Impact of Eccentric Tube Shapes and Heat Pipes on Phase Change Material’s Thermal Charging

The thermal charging performance of phase change material (PCM) in an eccentric tube and shell system is investigated through numerical analysis. Various shapes of eccentric tubes, including circular, semi-circular, triangular, inverted triangular, square, and C-shape, are considered. The PCM mass and shell diameter remain consistent across all tube geometries. Moreover, vertical heat pipes (HPs) are utilized to connect the heat source eccentric tube wall and the PCM stored in the shell. The examination evaluates the consequences of the tube shape and HPs using liquid fraction, temperature time history and contours, enhancement ratio, total energy storage, and mean power as performance indicators. The findings demonstrate that non-circular cases exhibit a shorter melting time than circular tube cases. The C-shape tube has the (Largest) 30.3% less thermal charging time than the circular tube, and the mean power is 39% higher. Moreover, adding HPs increases the mean power by up to 241% more than the circular tube, and reduces thermal charging time by about 72.2%. The inverted triangular tube exhibits the highest energy charge capability within the selected options.

Comprehensive CT Imaging Analysis of Primary Colorectal Squamous Cell Carcinoma: A Retrospective Study.

The aim of this study was to evaluate the findings of CT scans in patients with pathologically confirmed primary colorectal squamous-cell carcinoma (SCC). The clinical presentation and CT findings in eight patients with pathologically confirmed primary colorectal squamous-cell carcinoma were retrospectively reviewed by two gastrointestinal radiologists. Hematochezia was the most common symptom (n = 5). The tumors were located in the rectum (n = 7) and sigmoid colon (n = 1). The tumors showed circumferential wall thickening (n = 4), bulky mass (n = 3), or eccentric wall thickening (n = 1). The mean maximal wall thickness of the involved segment was 29.1 mm ± 13.4 mm. The degree of tumoral enhancement observed via CT was well enhanced (n = 4) or moderately enhanced (n = 4). Necrosis within the tumor was found in five patients. The mean total number of metastatic lymph nodes was 3.1 ± 3.3, and the mean short diameter of the largest metastatic lymph node was 16.6 ± 5.7 mm. Necrosis within the metastatic node was observed in six patients. Invasions to adjacent organs were identified in five patients (62.5%). Distant metastasis was detected in only one patient. In summary, primary SCCs that arise from the colorectum commonly present as marked invasive wall thickening or a bulky mass with heterogeneous well-defined enhancement, internal necrosis, and large metastatic lymphadenopathies.

Carotid atherosclerotic plaque predicts progression of intracranial artery atherosclerosis: A MR imaging-based community cohort study

PurposeIntracranial artery atherosclerosis (ICAS) progression is associated with stroke. However, the association of carotid plaque with ICAS progression among stroke-free participants is still unclear. This study aimed to evaluate the association between carotid plaque and ICAS progression in stroke-free participants. MethodStroke-free participants were recruited from a community-based cohort study. All participants underwent questionnaire interviews, blood tests, and high-resolution vessel wall magnetic resonance (MR) imaging at baseline and follow-up for around three years. The atherosclerotic plaque was defined as eccentric wall thickening on MR imaging. The presence, location, total number, and burden (maximum wall thickness, length, and stenosis) of carotid and intracranial plaque were evaluated. ICAS progression was defined as the number increased or plaque burden (maximum wall thickness, length, or stenosis increase) increased by ≥ 20 %. The association between carotid plaque and ICAS progression was evaluated using multivariable logistic regression. ResultsOf the 312 participants (mean age at baseline: 59.85 ± 13.04 years; 136 males) who completed baseline and follow-up studies with a mean time interval of 3.15 ± 0.59 years, 85 (27.24 %) had progression of ICAS during follow-up. At least one carotid plaque was detected at baseline in 167 (53.53 %) participants. In the multivariable logistic analysis, carotid plaque was a significant predictor for the progression of ICAS (odds ratio, 2.04; 95 % confidence interval, 1.06–3.92; P = 0.032). ConclusionsCarotid plaque is associated with intracranial artery atherosclerosis progression in stroke-free population. Our findings suggest that carotid plaque may be an effective predictor for intracranial artery atherosclerosis progression.

STATIC BEARING CAPACITY OF STEEL-PLATE COMPOSITE WALLS

The features of the behavior of steel-plate composite walls for static loads are considered. Based on the analysis of modern technical and regulatory documentation, the rationale for the chosen research topic is given. A review of the literature is performed, and the features of development are noted. A detailed description and features of the experimental structures under study and the materials used are presented. The features of the test are considered, and the test equipment is described. Analytical and numerical calculations of structures for eccentric compression have been performed. The description of the calculation complex and the used models of materials is presented; the description of numerical models, the features of their construction and calculation are given, the results of calculations are presented – stress distributions, deformations, features of cracking. The general types of experimental eccentric compression wall models are presented, the nature of the loss of bearing capacity of experimental structures is described, and a picture of destruction is presented. The analysis of the experimental data obtained and their comparison with analytical and numerical calculations are performed.

Recanalized paramedian thalamoperforators after intraarterial tirofiban treatment in a patient with bilateral fetal-type PCAs (P8-5.028)

<h3>Objective:</h3> NA <h3>Background:</h3> There are increasing evidence that support the treatment effect of intraarterial tirofiban during endovascular thrombectomy in acute ischemic stroke. Here, we report a patient with bilateral fetal-type PCAs, whose paramedian perforating thalamic-mesencephalic arteries were recanalized after intraarterial tirofiban treatment during thrombectomy. <h3>Design/Methods:</h3> NA <h3>Results:</h3> A 78-year-old woman presented to the emergency room with acute onset of drowsy mentality, gaze palsy and quadriplegia (NIHSS 9). She had a history of hypertension and diabetes. Brain CT scan revealed no definite early ischemic damage and CTA showed steno-occlusion at the left distal VA and bilateral fetal type PCAs. Brain perfusion CT showed perfusion delay in posterior circulation territory. Under local anesthesia, an 6F Envoy^® catheter (Codman) was placed in the left distal VA of distal V2 segment. The angiography revealed the distal VA occlusion (V4 segment) (Fig. 1A). Suction thrombectomy was performed twice using 5F Sofia^® catheter (Microvention), and no clot was extracted (Fig. 1B). Recanalization of left distal VA with underlying severe ICAS at the occlusion site (Fig. 1C). Delayed angiogram showed subtle re-occlusion tendency of left distal VA, 0.5mg of intraarterial tirofiban was injected. Successful recanalization (mTICI 2C) with further recanalized paramedian perforating thalamic-mesencephalic arteries on distal BA after SCA branches was achieved (Fig. 1D). Follow-up brain MRI showed acute infarction at the posterior circulation territory including bilateral thalami. MRA showed patent left distal VA with underlying severe ICAS, and vessel wall MRI showed eccentric wall thickening without contrast enhancement or plaque hemorrhage. The patient recovered well at 1 week (NIHSS 0). <h3>Conclusions:</h3> In a patient with bilateral fetal type PCAs, distal BA could end after SCA branches and this site should be evaluated cautiously, because thalamoperforators could originate. Intraarterial tirofiban could be helpful to recanalize perforating arteries during thrombectomy. <b>Disclosure:</b> Dr. Baik has nothing to disclose.

MRI findings of sporadic/simple lymphoepithelial cyst of the parotid gland.

This study aimed to determine the MRI features of sporadic/simple lymphoepithelial cyst (SLEC) of the parotid gland. Ten patients (seven men, three women; mean age, 60years; age range, 38-77years) with histopathologically and clinically proven SLEC of the parotid gland who underwent MRI before surgical resection were enrolled in this study. No enrolled patient had HIV infection or Sjögren syndrome. MRI findings of SLEC were retrospectively assessed. We confirmed 10 SLECs larger than 10mm with a mean maximum diameter of 26.6mm (range, 12-42mm). Nine patients (90%) had a single cyst, and one (10%) had a large cyst accompanied by small cysts (<10mm) within the ipsilateral parotid gland. Eight SLECs (80%) were unilocular, and two (20%) were bilocular, with complete septa. Among seven SLECs (70%) with internal septa, five unilocular SLECs (50%) had incomplete septa. Six SLECs (60%) had eccentric cyst wall thickening, and five (50%) were surrounded by small solid nodules that were isointense relative to lymph node. On T1-weighted images, all cyst contents were homogeneously hyperintense relative to cerebrospinal fluid. SLECs of the parotid gland are usually single unilocular lesions. Internal septa, eccentric cyst wall thickening, and small solid nodules surrounding the lesion were often observed. Cyst contents are always homogeneously hyperintense on T1-weighted images.

Analytical study on behaviour and performance of infilled frame structure with reinforced eccentric opening

This numerical analysis has discussed the behaviour of the frame structure with eccentric infill wall opening modelled with shell and strut elements. In the beginning, validation models were created by following the laboratory tests results. Then, a simple one-storey infill frame structure with an opening was modelled with varying ratios by taking the strut angle formed to obtain an equation for the strut width that corresponds to the behaviour of shell element model with strut angles variation. The strut width equation was then applied to the 3-storey infill frame structures. The behaviour comparison between the strut and shell element model was then investigated by linear and nonlinear static analysis. The strut width equation for infill wall frame with eccentric openings (Weo) is determined by modifying the stiffness coefficient (Ce) based on the opening ratio. The application of the Weo equation to the infill frame model showed that the strut model had a comparable behaviour to the shell element model. The drift ratio comparison showed that the smaller the strut angle, the greater the structure stiffness. The pushover analysis shows the infilled frame model was able to withstand a larger base shear force than the open frame model.

Utility of high-resolution magnetic resonance vessel wall imaging in differentiating between atherosclerotic plaques, vasculitis, and arterial dissection

PurposeDifferentiating between atherosclerosis, vasculitis, and dissection is a diagnostic challenge because of inconclusive findings on conventional imaging and some overlap in the vessel wall patterns. The aim of this study was to determine whether vessel wall MRI patterns can differentiate between these vasculopathies.MethodsWe retrospectively reviewed 3T high-resolution vessel wall imaging studies of patients diagnosed with atherosclerotic plaques, vasculitis, and dissection. The patterns of involvement, wall enhancement, and T1 and T2 signals, as well as the specific patterns, were assessed and compared between the three diseases.ResultsFifty-nine patients with atherosclerosis (n = 33), vasculitis (n = 13), and dissection (n = 13) were enrolled. There were significant differences in the pattern of involvement between the three groups (P < 0.001), with concentric wall thickening in vasculitis patients (84.6%) and eccentric wall thickening in atherosclerosis (97%) and dissection (92.3%) patients. There was also a significant difference in the specific pattern (P < 0.001), with intimal flap (76.9%) and intramural hematoma (23.1%) in dissection patients and intraplaque hemorrhage (18.2%) in atherosclerosis patients. Furthermore, subgroup analysis showed a significant difference in the wall enhancement pattern between atherosclerosis and vasculitis patients (P < 0.05). Finally, there was a significant difference in the location of involvement between the three groups (P < 0.001).ConclusionBy using the pattern of involvement, wall enhancement, and specific patterns, vessel wall MRI can help differentiate between atherosclerosis, vasculitis, and dissection.

Settling behavior of spherical particles in eccentric annulus filled with viscous inelastic fluid

Hole cleaning is a complex process as there are many variables affecting cuttings removal (e.g. drilling fluid type, density, flow rate and rheological properties, cuttings size, drill pipe rotation speed). With the increasing number of drilling small diameter wells (e.g. coiled tubing drilling applications, ultra-deep wells drilled for exploitations of unconventional oil and gas resources), the wall resistance of the micro annulus also emerges as one of the most critical factors affecting the cuttings accumulation in wellbore. The eccentricity of drill pipes commonly observed during the drilling process of ultra-deep well and coiled tubing well makes the wall resistance effect on the cuttings transport even more prominent. Understanding the wall resistance effect on the particle settling behavior in eccentric annuli is, therefore, crucial for hydraulic design of efficient cuttings transport operations in these wells. In this study, a total of 196 sets of particle settling experiments were carried out to investigate the particle settling behavior in eccentric annuli filled with power-law fluids. The test matrix included the eccentricity ranges of 0–0.80, the dimensionless diameter ranges of 0.13–0.75 and the particle Reynolds number ranges of 0.09–32.34. A high-speed camera was used to record the particle settling process and determine the influences of the eccentricity, the dimensionless diameter, the fluid rheological properties, and the solid particle characteristics on the wall factor and the particle settling velocity. The functional relationship among the dimensionless diameter, the particle Reynolds number, and the wall factor was determined by using the method of controlling variables. An eccentric annulus wall factor model with average relative error of 5.16% was established. Moreover, by introducing Archimedes number, an explicit model of particle settling velocity in the eccentric annulus with average relative error of 10.17% was established. A sample calculation of particle settling velocity was provided to show the application of the explicit model. Results of this study can be used as a guideline by field engineers to improve hydraulic design of cuttings transport operations in concentric and eccentric annuli.

Proliferative Vasculopathy Associated With Antiphospholipid Antibodies in Patients With Neurological Symptoms.

BackgroundProliferative vasculopathy (PV) associated antiphospholipid syndrome (APS) in the central nervous system is a rare un(der)recognized form of extra-criteria manifestations of APS. This study investigated the angiographic characteristics of cerebral and cervical arteries in patients with PV associated with antiphospholipid antibodies (aPLs).MethodsPatients with aPLs, neurologic symptoms and diffuse luminal narrowing on brain or neck magnetic resonance angiography were selected from electronic medical records. Vascular wall and intraluminal pathology were examined by high-resolution vessel wall MR imaging (VW-MRI).ResultsA total of 11 patients (six men and five women) with PV-aPL, of median (interquartile range) age 42 (34–61) years, were included. Median anticardiolipin antibodies IgG titer was 78.9 (28.2–134.0) units and anti-beta 2 glycoprotein I antibodies (aB2GPIs) IgG titer was 227.2 (0.0–1012.1) units. All patients had diffuse luminal narrowing in the carotid basilar and/or cerebral arteries, five in the internal carotid artery (ICA); two each in the middle cerebral artery (MCA) and vertebral artery; and one each in the basilar artery (BA) and posterior cerebral artery. On VW-MRI, four patients showed concentric thickening of the vascular walls of the ICA and/or MCA and two showed mild eccentric wall thickening of the ICA or BA. All patients received antithrombotic treatment. In two patients with extremely high aB2GPIs titer, diffuse narrowing progressed despite treatment with antithrombotic agents on follow-up imaging.ConclusionsThis study suggests that PV-aPL might be a distinct extra-criteria manifestation of APS that can manifest as long-segmental diffuse stenosis of cerebral and cervical arteries. It should be considered in relatively young patients with neurologic symptoms and aPLs.

Seismic performance of single-storey light timber-framed buildings braced by gypsum plasterboards considering rigidity of ceiling diaphragms

Light timber framed (LTF) structures provide a cost-effective and structurally efficient solution for low-rise residential buildings. This paper studies seismic performance of single-storey LTF buildings sheathed by gypsum-plasterboards (GPBs) that are a typical lining product in New Zealand houses. Compared with wood-based structural panels, GPBs tend to be more susceptible to damage when they are used in bracing walls to resist earthquake loads. This study aims to provide insights on how the bracing wall irregularity allowed by the current New Zealand standard NZS 3604 and the in-plane rigidity of ceiling diaphragms affect the overall seismic performance of these GPB-braced LTF buildings. Nonlinear time-history analyses were conducted on a series of single-storey baseline buildings with different levels of bracing wall irregularities and ceiling diaphragm rigidity. The results showed significant torsional effect caused by the eccentric bracing wall layout with semi-rigid/rigid ceiling diaphragms. On average, bracing wall drift demand caused by the extreme bracing wall irregularities was three times of that in the regular bracing wall layout under the rigid diaphragm assumption. This finding agreed well with the house survey after the 2011 Canterbury Earthquake in which significantly more damage was observed in the houses with irregular bracing wall layouts and relatively rigid diaphragms. Therefore, it is recommended to limit the level of bracing wall eccentricity and ensure the sufficiently rigid diaphragms to avoid excessive damage in these LTF buildings in future events.

Drug-Coated Balloon-Oriented Angioplasty for Severe Symptomatic Atherosclerotic MCA Stenosis in Young Adults.

PurposeThe clinical significance of endovascular therapy in young patients with symptomatic intracranial atherosclerotic stenosis is not clear. We aimed to report our preliminary findings on the safety and effectiveness of a new endovascular treatment strategy, drug-coated balloon (DCB)-oriented angioplasty for young adults with severe symptomatic atherosclerotic middle cerebral artery (MCA) stenosis.MethodsWe retrospectively retrieved the data of seven young patients aged 21–32 years old with severe symptomatic atherosclerotic MCA stenosis treated with DCB-oriented angioplasty from January 2018 to October 2020. We collected clinical presentations, perioperative complications, and clinical and radiological outcomes.ResultsThe DCB was successfully dilated at the lesions in all seven patients and good antegrade perfusion was achieved in five. The other two patients underwent remedial stent implantation due to residual stenosis >50% and unstable antegrade perfusion after DCB dilatation. However, none of the patients had perioperative complications. There were no recurrent ischemic symptoms after a mean clinical follow-up period of 15.4 ± 6.9 months. Repeat vascular images of the patients showed no restenosis at 3- or 6-month imaging follow-up periods. High-resolution MRI (HRMRI) was completed in all the patients before the angioplasty procedure and at follow-up. Focal eccentric wall thickening was present at the site of stenosis preoperatively; however, the plaques had disappeared by the time of follow-up for all patients.ConclusionDCB-oriented angioplasty may be safe and effective for young patients with severe symptomatic atherosclerotic MCA stenosis.

Acute Limited Intimal Tear of the Right Aortic Sinus.

HomeRadiology: Cardiothoracic ImagingVol. 3, No. 6 Previous Images in Cardiothoracic ImagingFree AccessVascular ImagingAcute Limited Intimal Tear of the Right Aortic SinusLucas de Pádua Gomes de Farias , Márcio Campos Sampaio, José Honório de Almeida Palma da Fonseca, Luciana de Pádua Silva BaptistaLucas de Pádua Gomes de Farias , Márcio Campos Sampaio, José Honório de Almeida Palma da Fonseca, Luciana de Pádua Silva BaptistaAuthor AffiliationsFrom the UnitedHealth Group Brazil, Hospital Samaritano Paulista, Avenida Brigadeiro Luís Antônio 1895, Bela Vista, São Paulo, SP 01317-002, Brazil.Address correspondence to L.d.P.G.d.F. (e-mail: [email protected]).Lucas de Pádua Gomes de Farias Márcio Campos SampaioJosé Honório de Almeida Palma da FonsecaLuciana de Pádua Silva BaptistaPublished Online:Dec 2 2021https://doi.org/10.1148/ryct.210239MoreSectionsPDF ToolsImage ViewerAdd to favoritesCiteTrack CitationsPermissionsReprints ShareShare onFacebookTwitterLinked In Limited intimal tears (LITs) are uncommon but potentially lethal lesions within the dissection spectrum, occurring in approximately 5% of patients presenting with acute aortic syndrome (1). LITs are classified as a “class 3 of intimal tear” and represented by intimomedial tears with an eccentric aortic wall bulge but without substantial hematoma (2). While the edges of an LIT can be undermined to a variable degree and filled with small amounts of blood or clot, there is no propagation of the dissection plane along the aorta and no exit tear and double-barrel flow channel as in classic aortic dissection (1,3). LITs may evade identification at transesophageal echocardiography or CT because of the limited extent of undermined intimal layers and a minimal amount of blood in the dissected aortic wall. This imaging pitfall can result in progression of dissection, cardiac tamponade, or aortic rupture causing potentially lethal outcomes (1,2,4). Furthermore, the diagnosis of LITs may be missed if conventional diagnostic criteria that are dependent on the presence of an intimal flap are applied (4). Awareness of this entity, high index of suspicion at CT angiography with use of appropriate reconstruction techniques for the aortic root may allow timely patient management (1) (Figure).Images in a 62-year-old man who presented to the emergency department with acute chest pain. (A) Short-axis view of the aortic root, (B) three-chamber view, (C–E) three-dimensional volume-rendered images, and (F) intraoperative view after median sternotomy with extracorporeal circulation show an eccentric bulge of the right aortic sinus (R) with the presence of a focal limited tear (arrowhead). This is represented by focal linear “flaps” with undermined edges, as a bandlike outpouching where the right coronary artery (RCA) took off. The patient underwent graft replacement of the ascending aorta and aortic valve replacement. AA = ascending aorta, LA = left atrium, LV = left ventricle, LM = left main artery, R/L/NC = right/left/noncoronary aortic sinus.Download as PowerPointOpen in Image Viewer Disclosures of conflicts of interest: L.d.P.G.d.F. No relevant relationships. M.C.S. No relevant relationships. J.H.d.A.P.d.F. No relevant relationships. L.d.P.S.B. No relevant relationships.Keywords: CT Angiography, Vascular, Aortic RootAuthors declared no funding for this work.

Colorectal endometriosis with a large polypoid lesion

A 39-year-old woman was referred to our hospital because of a positive fecal occult blood test result. She had undergone uterine myomectomy 6 years earlier, and she had been treated with levothyroxine for hypothyroidism after thyroidectomy for Graves’s disease. A physical examination revealed a left-sided abdominal mass without tenderness. A laboratory test showed that the levels of serum tumor markers were within normal range. A barium enema revealed a 4-cm protruding lesion in the descending colon (A). The lesion looked like a submucosal tumor with reddish mucosa and dilatated vessels (B). Magnifying endoscopy with crystal violet staining showed 2 types of pit pattern: most was regular and rounded, whereas a small area had an enlarged and irregular pit pattern (C). Surgical histopathologic examination confirmed that the protruding lesion was composed of endometrial glands and stroma surrounded by smooth muscle bundles (D, H&E, orig. mag. ×40). The results of testing for immunohistochemistry, estrogen receptor (ER), and progesterone receptor were positive. Therefore, we diagnosed polypoid endometriosis. Retrospectively, a biopsy specimen from the lesion with irregular pits showed that a few glands were positive for ER (E, Immunohistochemistry for ER, orig. mag. ×200). Colorectal endometriosis usually presents as eccentric wall thickening and surface nodularities, and diagnosis by endoscopic biopsy is difficult. Our case suggests that magnifying endoscopy is useful for diagnosis with target biopsy for intestinal endometriosis.

Cardiovascular Risk Factors Affect Specific Segments of the Intracranial Vasculature in High-Resolution (HR) Vessel Wall Imaging (VWI)

ObjectivesLuminal-based imaging have identified different risk factors for extracranial and intracranial atherosclerosis (ICAS), but these techniques are known to underestimate the true extent of the disease. High-resolution (HR) vessel wall imaging (VWI) has recently gained recognition as a valuable tool in the assessment of ICAS. The aim of this study is to determine the association between cardiovascular risk factors and specific intracranial vessel segment involvement using HR-VWI. Materials and methodsFrom January 2017 to January 2020, consecutive patients ≥ 18 years-old undergoing HR-VWI of the brain were identified. Patients with history of primary or secondary vasculitis, reversible cerebral vasoconstriction syndrome, or moya-moya were excluded. The presence of vessel wall thickening and enhancement were assessed in the perpendicular plane for each vessel segment by two neuroradiologists. Univariate and multivariate analyses were performed to assess associations between imaging findings and cardiovascular risk factors. Interrater reliability was calculated. ResultsSeventy-one patients (39 men; mean age: 55.9 years) were included. Vessel wall enhancement was seen in 39/71 (55%). A total number of 105 vessel segments demonstrated abnormal enhancement and 79/105 (75%) had an eccentric pattern. Eccentric vessel wall enhancement was independently associated with age >65 years-old in the ICA (OR 9.0, CI 2.1 – 38.2, p < 0.01) and proximal MCA (OR 4.0, CI 1.2 – 13.2, p = 0.02), and with hyperlipidemia in the posterior circulation (OR 44.0, CI2.9-661.0, p<0.01). ConclusionThere is a significant association between eccentric vessel wall enhancement of the ICA and proximal MCA in patients with age > 65; and of the proximal posterior circulation (basilar - PCA1) with hyperlipidemia.

Computed Tomographic Findings of Malignant Bowel Neoplasms: A Retrospective Study

Introduction: Malignant neoplasms of bowel particularly colorectal carcinomas are third commonest cause of death all over world. Computed Tomography (CT) plays a very important role in evaluation of malignant bowel neoplasms. CT examination for gastrointestinal tract evaluates the intestinal lumen along with demonstration of intestinal wall, adjacent tissues and solid viscera. Aim: To evaluate malignant neoplasms of small and large intestine and also to define the various CT findings in malignant bowel neoplasms, extra-intestinal involvement to stage intestinal neoplasms and to accurately characterise the tumour histologically as far as possible. Materials and Methods: A retrospective descriptive study included 38 patients who were proven to have malignancy of bowel on biopsy, underwent CT abdomen in major public hospital in a period of from November 2014 to May 2017 and evaluated for various CT findings in malignant bowel neoplasms in terms of involved intestine, length of diseased intestinal segment, degree of intestinal wall thickening, extra-intestinal involvement to stage bowel neoplasms and to accurately characterise the tumour histologically as far as possible. Data were tabulated and presented as frequency (n) and precentage (%). Results: In small intestine, ileum is the commonest site of involvement seen in 5 cases (13%), whereas rectum 10 cases (26.3%) was the commonest site of involvement in large intestine. Short segment involvement of bowel is more common 27 cases (71.1%) than long segment involvement 11 cases (28.9%). Circumferential wall thickening is more common in 33 cases (86.8%) than eccentric wall thickening 5 cases (13.2%). Lymph nodal involvement was seen in 17 cases (44%) and metastasis to liver was also seen in 11 cases (28.9%). Local invasion with involvement of surrounding structures was seen in 4 cases (10.5%). Adenocarcinoma was the commonest histological subtype seen in the highest number of 23 cases (60.5%), followed by lymphoma in 9 cases (23.6%), mucinous adenocarcinoma in 4 cases (10.5%) and few cases of about 2 cases (5.2%) were Gastrointestinal Stromal Tumour (GIST). Conclusion: Computed Tomography (CT) imaging findings like involved intestine, length of diseased intestinal segment, degree of intestinal wall thickening, extra intestinal involvement with respect to involvement of surrounding structures, lymph nodal involvement, distant metastasis along with histological type in most cases could be found, thus permitting tumour characterisation which can provide very useful guide in diagnosis of malignant neoplasms of small and large intestine.

S3589 Lymphocytic Gastritis: A Rare Form of Chronic Gastritis

INTRODUCTION: Lymphocytic gastritis (LG) is a form of chronic gastritis characterized by intraepithelial lymphocytes in the mucosa of the antrum or fundus. LG is considered a rare entity, presenting in <5% of gastric biopsies. (1) Little is known about the presentation, clinical significance, and evolution of disease. Current literature suggests a possible association between LG, Helicobacter pylori, and also Celiac disease. CASE DESCRIPTION/METHODS: A 58-year-old female with a past medical history of GERD, diverticulitis, and obesity presented to the Emergency Department with a 3 day history of sudden onset localized right upper quadrant abdominal pain. It was constant and sharp . Review of systems was positive for nausea and non-bilious emesis. On exam, the patient was comfortable and not ill appearing. Abdomen was soft, non-distended with normoactive bowel sounds. Palpation revealed mild tenderness of the epigastrium and right upper quadrant without rebound tenderness and guarding. Laboratory studies were normal and included: WBC, transaminases, total bilirubin, alkaline phosphatase, and lipase. An abdominal x ray showed no evidence of bowel obstruction or free intraperitoneal air. A CT abdomen with contrast showed a small focus of eccentric wall thickening near the mid sigmoid colon, concerning for possible neoplasm. The patient was treated with IV Zofran, Pepcid (discharged on this medication), and normal saline which resolved the abdominal pain. Due to CT abnormalities, the gastroenterology team was consulted, and the patient was scheduled for an outpatient esophagogastroduodenoscopy (EGD) and colonoscopy. EGD was normal, however, random gastric biopsies obtained for H. pylori from the gastric body, antrum, and incisura revealed increased CD3+ intraepithelial T cells consistent with LG. H.pylori immunohistochemical stain was negative. Colonoscopy (intubating the terminal ileum) revealed moderate sigmoid colon diverticulosis and internal hemorrhoids without colonic masses or ulcerations. She was continued on omeprazole and remains asymptomatic. DISCUSSION: Knowledge of LG remains limited. Due to a possible association between LG and Celiac disease a celiac serology panel and repeat EGD with duodenal biopsies will be obtained. This case serves to highlight a relatively new entity, its presentation, and possible associations.

Investigation and Analysis of Primary Lung Cancer with Endotracheal and Endobronchial Metastases

背景与目的气管支气管转移（endotracheal and endobronchial metastases, EEM）在肺癌中罕见，国外文献报道可发生于手术切除后，但国内目前尚未见相关报道，本研究旨在总结和分析肺癌发生EEM的临床特征。方法回顾2015年1月-2018年12月于北京大学第三医院确诊原发性肺癌并行支气管镜的患者，同时检索截至2020年2月PubMed检索系统中的病例，采集并比较两组患者的临床、病理、影像、支气管镜和预后等资料。结果我院共有6例肺癌伴EEM入选，发生率为0.62%（6/967），均为初诊为肺癌时即伴有EEM。鳞癌4例，腺癌1例，小细胞肺癌1例。Ⅲb期1例，Ⅳ期5例。中央型肺癌5例，周围型1例。EEM在支气管镜下表现为肺癌原发灶之外的气道黏膜结节或息肉性病变5例、局灶性黏膜异常1例。转移至对侧支气管5例，至同侧支气管和气管各1例。中位总生存期为7.5个月。从PubMed数据库共检索到13例，其中12例为肺癌术后随诊胸部计算机断层扫描（computed tomography, CT）异常继而确诊为EEM。中央型9例，鳞癌8例，EEM在CT上表现为腔内结节10例，气管壁局限增厚2例，支气管镜下均表现为气道黏膜结节或息肉样病变。转移至气管10例，至对侧支气管5例，至同侧支气管1例。结论EEM是原发性肺癌罕见的转移方式，可发生于初诊时，也可发生于术后，多见于晚期中央型鳞癌，预后差。

Performance of torsionally eccentric RC wall frame buildings designed to DDBD under bi-directional seismic excitation

The seismic performance of a class of reinforced concrete eccentric wall frame buildings under bi-directional ground motion excitation is investigated. For this purpose, four and eight-storey RC buildings comprising structural walls, flat-plates and gravity columns, having different strength and stiffness eccentricity and torsional restrain, are designed in accordance with the Direct Displacement Based Design (DDBD) method for damage control. The structures are analysed under static and dynamic inelastic response, considering ten ground motion record pairs, three intensity levels and different angles of incidence. Several global and local engineering demand parameters, namely, inter-storey drift, slab rotation, member plastic rotations and wall internal forces are evaluated and compared with the DDBD limits. It is shown that ground motion directionality effects are small, and the average drift and wall moment profiles are within DDBD predictions and, often, considerably lower than DDBD demanded. However, wall shear force and local inelastic demands are underpredicted by both DDBD and static inelastic analyses and, more significantly so, for the torsionally flexible structures.

Abstract MP03: Aortic Stiffening and Intracranial Atherosclerosis: The Atherosclerosis Risk in Communities Neurocognitive Study (ARIC-NCS)

Introduction: Stiffening of the aorta is associated with increased pulse pressure and transmission of pulsatile energy into the cerebral circulation. An association between increased aortic stiffening with intracranial atherosclerotic disease (ICAD) has not been widely studied. We tested the hypothesis that loss of aortic elasticity (i.e. higher aortic stiffness) is associated with a higher presence of ICAD. Methods: ARIC-NCS participants (n=1412; mean age: 76 years; 42% male; 30% Black) with measures of aortic stiffness and vascular brain magnetic resonance imaging (MRI) at the visit 5 (2011-2013) examination were included. Aortic stiffness was measured by carotid-femoral pulse wave velocity (cfPWV) using the VP-1000 Plus device (Omron Co., Japan). cfPWV was discretized into high vs. low aortic stiffness based on the upper 25 th percentile, 13.4 m/s. Brain MRI was performed on 3.0 Tesla scanners using a standardized protocol that included an MR angiography (MRA) and high isotropic resolution vessel MRI. Presence of ICAD was defined as eccentric wall thickening with or without luminal stenosis on MRA. We first examined the functional form relationship between continuous measures of cfPWV and ICAD. Comparing those with high vs. low aortic stiffening, we estimated the prevalence odds of ICAD using logistic regression. Models were adjusted for age, sex, race-center, education, smoking, heart rate, blood-pressure lowering medication, diabetes, LDL-cholesterol, and minutes/week of physical activity. Sampling weights were used for generalizability to the full ARIC cohort at visit 5. We tested for effect modification by race, sex, diabetes, central systolic blood pressure, and use of blood pressure-lowering medication. Results: The mean cfPWV was higher among participants with ICAD (12.6 ± 3.2 m/s) compared to those without ICAD (11.2 ± 2.9 m/s). cfPWV was associated with ICAD in a monotonic, linear fashion (p&lt;0.05). The presence of ICAD was 50.6% among participants with high aortic stiffness (cfPWV above the upper 25th percentile; n=354) compared to 30.2% among participants with low aortic stiffness (n=1058). Compared to participants with low aortic stiffness, those with high aortic stiffness had two-fold higher odds of ICAD (odds ratio (OR): 1.97, 95% confidence interval (CI): 1.68, 2.33). No statistically significant modification of this association was observed. Results were robust to exclusions for prevalent stroke (n=43) and prevalent cardiovascular disease (n=153). Conclusions: Aortic stiffness, a highly prevalent trait among older men and women, is associated with ICAD presence quantified by magnetic resonance angiography. Aortic stiffness, its risk factors and the factors associated with the preservation of aortic elasticity, may play a role in modifying the risk of intracranial atherosclerosis.