Clinical significance of mesenteric panniculitis-like abnormalities on abdominal computerized tomography in patients with malignant neoplasms

AIM To clarify the association of malignancy with mesenteric panniculitis-like changes on computed tomography(CT).METHODS All abdominal CT scans performed at North Shore University HealthS ystem showing mesenteric panniculitis from January 2005 to August 2010 were identified in the Radnet(Rad Net Corporation, Los Angeles, CA) database. Patients with a new or known diagnosis of a malignancy were included for this analysis. Longitudinal clinical histories were obtained from electronic medical records.RESULTS In total, 147794 abdominal CT scans were performed during the study period. Three hundred and fiftynine patients had mesenteric panniculitis(MP)-like abnormalities on their abdominal CT. Of these patients, 81 patients(22.6%) had a known history of cancer at the time of their CT scan. Nineteen(5.3%) had a new diagnosis of cancer in concurrence with their CT, but the majority of these(14/19, 74%) were undergoing CT as part of a malignancy evaluation. Lymphomas were the most common cancers associated with MPlike findings on CT(36 cases, 36%), with follicular lymphoma being the most frequent subtype(17/36). A variety of solid tumors, most commonly prostate(7) and renal cell cancers(6) also were seen. CT follow up was obtained in 56 patients. Findings in the mesentery were unchanged in 45(80%), worsened in 6(11%), and improved in 5 patients(9%). Positron emission tomography(PET) scans performed in 44 patients only showed a positive uptake in the mesenteric mass in 2 patients(5%). CONCLUSION A new diagnosis of cancer is uncommon in patients with CT findings suggestive of MP. MP-like mesenteric abnormalities on CT generally remain stable in patients with associated malignancies. PET scanning is not recommended in the evaluation of patients with mesenteric panniculitis-like findings on CT.

Temporal Trends in Radiation Dose Associated with Coronary Computed Tomography Angiography

Background: In 2010, the International Atomic Energy Agency launched the “3A’s campaign” as an effective tool for primary cancer prevention. In 2011, the American Association of Physicists in Medicine recommended the size specific dose estimate (SSDE). Objectives: To audit doses of Coronary CT Angiography (Coronary CTA) in tertiary care referral center. Methods: We reviewed 998 consecutive Coronary CTA (from 2007 to 2012). Doses (CTDIvol mGy), DLP (mGy*cm), effective dose (DLP*0.014, mSv) were on-line archived. SSDE was estimated retrospectively. Appropriateness score was evaluated for exams performed from the 2010. Results: Overall median dose per Coronary CTA was 49.7 mGy for CTDIvol, 55.5 mGy for SSDE, 994.96 mGy*cm for DLP, 13.9 mSv for effective dose. Median DLP decreased over time (1452.94 in 2007, 1605.56 in 2008, 1113.49 in 2009, 759.99 in 2010, 448.61 in 2011 and 497.88 mGy*cm in 2012, p < 0.0001). SSDE was proportional to the size dependent factor (SDF);in patients with SDF > 1 (88%) CTDIvol underestimated SSDE (48.49 vs 57.19 mGy), whilst in patients with SDF < 1 (12%) CTDIvol overestimated SSDE (56.46 vs 50.3 mGy). Scans were appropriate in 58%, uncertain in 24%, and inappropriate in 18% of cases. Doses were similar in appropriate, uncertain or inappropriate examinations and in excellent-to-good (81%) vs. sufficient-to-poor (19%) image quality exams. Conclusions: Coronary CTA reference doses can be very misleading. SSDE can allow individual technique optimization. The dose is similar in appropriate and inappropriate examinations, and unrelated to image quality. The rate of inappropriate examinations is still too high even after dissemination of guidelines.

The Different Patterns of Coronary Artery Calcification in Acute and Chronic Coronary Syndromes Determined by Electron Beam Computed Tomography

Objectives To compare the different patterns of coronary artery calcification (CAC) in acute and chronic coronary syndromes utilizing electron beam computed tomography. Background Pathologic, angiographic, and intracoronary ultrasound studies revealed sharp differences in the plaque morphology between patients with acute versus chronic coronary syndromes. Whether there are different patterns of coronary artery calcification in patients with stable angina pectoris (SAP) and in those with unstable angina pectoris (UAP) or acute myocardial infarction (AMI), however, remains unclear. Methods Two hundred and sixty - four patients, including 67 with SAP, 94 with UAP and 103 with AMI were studied with electron beam computed tomography for analysis of coronary artery calcification and with selective coronary angiography for determination of atherosclerotic lesions. CAC prevalence and calcium score were compared among three groups, and relation of CAC to the severity of atherosclerotic disease in the SAP and UAP patients was separately analyzed. Results Prevalence of CAC was 100 % in the SAP patients, significantly higher than the 87. 23 % in UAP patients and 86. 41 % among the patients with AMI ( P < 0. 05) . More patients and arteries in the SAP group had severe forms of calcium than those in the UAP and AMI group ( P < 0. 01), and the mean LN [CS + 1] (natural logarithm transformation of calcium score) of the SAP patients was much greater than that of the UAP and AMI patients (P < 0.001). The distribution of vessels with various CAC by luminal stenosis was different between SAP and UAP patients. The average CAC extent of the infarct - related arteries was less severe than that of the noninfarct - related arteries. Conclusions U-tilizing electron beam computed tomography, we demonstrated that there exist different patterns of coronary artery calcification in patients with acute versus chronic coronary syndromes, which may provide insight into the differences observed in the clinical and pathologic development between these two types of coronary artery disease.

Application of polycapillary x ray lens to eliminate both the effect of x ray source size and scatter of the sample in laboratory tomography

A tomography device based on a conventional laboratory x ray source, polycapillary parallel x ray lens （PPXRL）, and polycapillary collimating x ray lens （PCXRL） is designed. The PPXRL can collect the divergent x ray beam from the source and focus it into a quasi-parallel x ray beam with a divergence of 4.7 rarad. In the center of quasi-parallel x ray beam, there is a plateau region with an average gain in power density of 13.8 and a diameter of 630μm. The contrast of the image can be improved from 28.9% to 56.0% after adding the PCXRL between the sample and the detector.

A new solid-conversion gas detector for high energy X-ray industrial computed tomography

A new type of solid-conversion gas detector is investigated for high energy X-ray industrial computed tomography (HECT). The conversion efficiency is calculated by using the EGSnrc Monte Carlo code on the Linux platform to simulate the transport process of photons and electrons in the detector. The simulation results show that the conversion efficiency could be more than 65%, if the X-ray beam width is less than about 0.2 mm, and a tungsten slab with 0.2 mm thickness and 30 mm length is employed as a radiation conversion medium. Meanwhile the results indicate that this new detector has higher conversion efficiency as well as less volume. Theoretically this new kind of detector could take place of the traditional scintillation detector for HECT.

Construction of a database of average cross-sections in Chinese proximal femurs

The process of constructing a database of average cross-sections in Chinese proximal femurs is described. The main goal of creating the database is for designing hip stems for Chinese patients. Methods for constructing the database are introduced. According to some existing software and programs developed by the authors, a database of average cross-sections in Chinese proximal femurs was built based on CT images of eighty femur-specimens. 3-D shape of a patient's proximal femurs can be reconstructed according to the database and X-ray radiographs. Theoretical analyses and results of clinical application indicate that the database can be used to design hip stems for Chinese patients.

Computerized tomography pleurography: a new method for detecting minor pleural lesion

Objectives To evaluate the ability of CT pleurography (CTP) in detecting minor pleural lesions in patients with pleural effusion and to assess its value in distinguishing malignant from benign pleural lesions. Methods A prospective study of 50 patients with pleural effusion was conducted using conventional CT and CTP. CT scan was run after injecting an appropriate amount of contrast medium into the pleural cavity. Results In 24 patients, all lesions detected by conventional CT were demonstrated by CTP. In 13 of 24 patients, CT pleurography detected additional lesions. In 20 of 26 patients with negative findings on conventional CT, CTP was capable of demonstrating the presence of pleural lesions. The sensitivity, specificity and accuracy of detecting pleural lesions were 25%, 100% and 30% for conventional CT, 86%, 100% and 87% for CTP, respectively. Conclusion CTP is superior to conventional CT in detecting and for the differential diagnosis benign and malignant pleural lesions.

月经前期发作的鼻源性头痛

随着鼻窦CT诊断和鼻内镜诊疗技术的发展，大量鼻部疾病导致的头痛得以治愈。根据2004年国际头痛协会的分类，鼻源性头痛的第二种类型——黏膜接触点性头痛（mucosa contact point headache），因为缺少典型的鼻部症状，而分散就诊于其他学科，长期得不到合理诊疗。我们近期总结了多例临床上没有典型的鼻部症状，而是以各种类型的头痛为主诉就诊于神经内科等专科的患者，经过会诊筛查，确诊为鼻源性黏膜接触点性头痛，通过鼻内镜手术治愈。其中包括1组女性患者，长期被误认为是月经前期头痛，通过治疗证明是黏膜接触点性头痛的一种特殊存在形式，撰文总结如下。

食管黏膜下异物的CT诊断

总结1995-2004年10年间治疗的351例食管异物患者其中首次手术未发现异物12例，X线透视检查无阳性表现15例。此27例患者．经CT薄层扫描确诊，行食管镜检查取出并治愈，现报道如下。

低剂量MSCT在肝癌患者腹部检查中的应用

目的探讨低剂量MSCT扫描降低肝癌患者腹部CT检查辐射剂量的价值。方法肝癌患者27例,初诊时采用常规螺旋扫描(常规扫描组),复诊时采用轴位扫描(低剂量组),两组均采用120 KV管电压及自动管电流技术,噪声指数为9,分别行平扫、动脉期及静脉期扫描。比较两组在图像质量、噪声值和辐射剂量的差异。结果两组图像质量评分、图像平扫、动脉期及静脉期噪声值比较差异无统计学意义(P>0.05);低剂量组有效剂量低于常规扫描组(P<0.05)。结论轴位扫描和自动管电流技术能有效降低肝癌患者腹部CT扫描的辐射剂量,并且图像质量好。

CT-脑立体定向手术的临床应用

目的 评价 CT-脑立体定向手术的临床应用价值。 方法 应用 CT-脑立体定向仪完成 2 8例次脑立体定向手术 ,分析其临床诊疗效果。 结果 立体定向活检术 10例 ,术后病理诊断明确 ;定向开放手术 12例 ,病灶一次切除 ;立体定向穿刺分流术 6例 ,术后症状改善明显。手术均一次成功 ,无手术并发症。 结论 CT-脑立体定向手术能精确定位 ,确定最佳手术路径 。

A CT-based radiomics nomogram for prediction of human epidermal growth factor receptor 2 status in patients with gastric cancer

Objective: To develop and validate a computed tomography(CT)-based radiomics nomogram for predicting human epidermal growth factor receptor 2(HER2) status in patients with gastric cancer.Methods: This retrospective study included 134 patients with gastric cancer(HER2-negative: n=87;HER2-positive: n=47) from April 2013 to March 2018, who were then randomly divided into training(n=94) and validation(n=40) cohorts. Radiomics features were obtained from the CT images showing gastric cancer. Least absolute shrinkage and selection operator(LASSO) regression analysis was utilized for building the radiomics signature. A multivariable logistic regression method was applied to develop a prediction model incorporating the radiomics signature and independent clinicopathologic risk predictors, which were then visualized as a radiomics nomogram. The predictive performance of the nomogram was assessed in the training and validation cohorts.Results: The radiomics signature was significantly associated with HER2 status in both training(P<0.001) and validation(P=0.023) cohorts. The prediction model that incorporated the radiomics signature and carcinoembryonic antigen(CEA) level demonstrated good discriminative performance for HER2 status prediction,with an area under the curve(AUC) of 0.799 [95% confidence interval(95% CI): 0.704-0.894] in the training cohort and 0.771(95% CI: 0.607-0.934) in the validation cohort. The calibration curve of the radiomics nomogram also showed good calibration. Decision curve analysis showed that the radiomics nomogram was useful.Conclusions: We built and validated a radiomics nomogram with good performance for HER2 status prediction in gastric cancer. This radiomics nomogram could serve as a non-invasive tool to predict HER2 status and guide clinical treatment.

MSCT灌注成像低剂量扫描对周围型非小细胞肺癌的病理分级的评价

目的探讨MSCT灌注成像低剂量扫描评价周围型非小细胞癌(non-small cell lung cancer,NSCLC)的病理分级的价值。方法 2009年9月～2011年2月期间经病理证实的周围型癌患者26例行MSCT灌注扫描,用Mann-Whitney法比较高、中分化程度及低分化、未分化肺癌的各参数差异,并运用Spearman相关分析有明显差异的灌注值与分化程度的相关性。结果高、中分化的肺癌的BF、PH高于低分化或未分化的肺癌,T1SPN-T1AA低于低分化或未分化的肺癌,其差异均有统计学意义(P<0.05)。BV、PS、MTT及T2SPN-T2AA无明显统计学差异(P>0.05)。肺鳞癌与肺腺癌之间诸参数值无明显统计学意义(P>0.05)。血流量(bllod flow,BF)、强化峰值(peak high,PH)与肺癌分化程度高低具有显著相关性(r分别为-0.398,-0.513,P<0.05)。结论 CT灌注成像低剂量扫描能有效地反映肺癌的分化程度,诸灌注参数中BF、PH、T1SPN-T1AA评价NSCLC的分化程度有一定帮助,其中BF和PH与肺癌分化程度具有显著相关性。

正常成人下腔静脉的CT测量

目的:测量100例正常成人下腔静脉(IVC)的各条径线及其位置,并探讨其临床应用意义。方法:分别测量右心房水平及第一肝门水平下腔静脉,并计算长短径的比值。在第一肝门水平的层面上,沿椎体的前缘做一水平线作为X轴,并紧贴该椎体右缘做与X轴垂直的Y轴,分别测量IVC中心距离X、Y轴的长度及IVC长轴与X轴角度。所有数据经统计学处理。结果:在右心房水平,IVC的短径无显著的年龄和性别差异(P>0.05),各性别、年龄组95%上限均<30mm。IVC长径存在显著的性别和年龄差异(P<0.05)。第一肝门水平,IVC短径无年龄差异(P>0.05),但存在性别差异(P<0.05),但两者95%上限均<22mm;而IVC长径以及IVC长径/短径不仅存在年龄差异,还存在性别差异(P<0.05)。IVC至X、Y轴距离无显著的年龄和性别差异(P>0.05),各性别、年龄组95%上限均<2.5cm和<1.0cm。IVC长轴与X轴的夹角为31°±5°,无显著的年龄差异(P>0.05),但存在性别差异(P<0.05),但两者95%上限均<60°。结论:右心房水平IVC短径是判断IVC增粗与否的敏感指标。CT可确定第一肝门水平正常IVC的位置及与X轴的夹角范围,为肝肾间隙病变对IVC推移的判断提供诊断参考。

Findings of non-pathologic perfusion defects by CT arterial portography and non-pathologic enhancement of CT hepatic arteriography

AIM To recognize the characteristic findings of non pathologic perfusion defects with CT arterial portography (CTAP) and nonpathologic enhancement found in CT hepatic arteriography (CTHA). METHODS The manifestations of nonpathologic perfusion defects with CTAP and non pathologic enhancement found in CTHA were analyzed in 50 patients with primary hepatocellular carcinoma. RESULTS The false positive rate of perfusion defects detected in CTAP was 15 1%. The shapes of perfusion defects were peripheral wedge, small, round, and patchy. The occurrence rate of non pathologic enhancement found in CTHA was 22 0%. The shapes of non pathologic enhancement were small, round, irregular, and wedge. CONCLUSION There was a high frequency of non pathologic perfusion defects detected with CTAP and non pathologic enhancement found in CTHA. The simultaneous use of both procedures may help decrease the false positive rate, and increase the veracity of diagnosis for hepatocellular carcinoma.

减影CTA成像技术在颅内动脉瘤诊断中的应用

目的:探讨64排螺旋CT减影CTA成像技术对颅内动脉瘤的诊断作用。方法:对120例临床蛛网膜下腔出血的病人行CT检查,重建技术用最大密度投影(MIP)和容积再现(VR)。以手术及部分数字减影血管造影术(digital subtraction angiography,DSA)为标准评价减影CTA和常规CTA检查结果,采用双盲法评价图像质量。结果:减影CTA检出动脉瘤122个,敏感性为100%,特异性为100%,阴性似然比为0.000 0;常规CTA检出动脉瘤119个,漏检3个颈内动脉床突下的动脉瘤,敏感性为97.5%,特异性为100%,阴性似然比为0.025 0。结论:减影CTA技术对颈内动脉床突下动脉瘤的检出具有明显的优势。

Role of cardiac CTA in estimating left ventricular volumes and ejection fraction

Left ventricular ejection fraction(LVEF)is an impor-tant predictor of cardiac outcome and helps in makingimportant diagnostic and therapeutic decisions suchas the treatment of different types of congestive heartfailure or implantation of devices like cardiac resynchro-nization therapy-defibrillator.LVEF can be measuredby various techniques such as transthoracic echo-cardiography,contrast ventriculography,radionuclidetechniques,cardiac magnetic resonance imaging andcardiac computed tomographic angiography(CTA).Thedevelopment of cardiac CTA using multi-detector rowCT(MDCT)has seen a very rapid improvement in thetechnology for identifying coronary artery stenosis andcoronary artery disease in the last decade.During theacquisition,processing and analysis of data to studycoronary anatomy,MDCT provides a unique opportunityto measure left ventricular volumes and LVEF simulta-neously with the same data set without the need foradditional contrast or radiation exposure.The develop-ment of semi-automated and automated software to measure LVEF has now added uniformity,efficiency and reproducibility of practical value in clinical practice rather than just being a research tool.This article will address the feasibility,the accuracy and the limitations of MDCT in measuring LVEF.

原发性骨淋巴瘤的影像学表现

目的分析原发性骨淋巴瘤(PBL)的影像学表现,提高对该病的认识。方法搜集经活检及手术病理证实的PBL患者20例,回顾性分析其影像学特点。结果 20例中,股骨6例、颅骨4例、胫骨3例、脊柱3例、锁骨、肱骨、骶骨及髂骨各1例。根据骨质破坏特点,分为浸润型11例,溶骨型7例,骨质硬化型1例,混合型1例,其中3例合并病理性骨折。19例有较明显的软组织肿块,CT检查13例软组织肿块密度稍低于邻近肌肉组织,内无坏死及钙化;MRI检查9例,病灶T1WI上呈等、稍低信号,其中5例在T2WI上表现为稍高信号,4例为不均匀信号,增强后较明显强化。结论 PBL影像学有一定的特点:常伴有明显的软组织肿块,临床症状相对较轻,骨破坏以浸润型、溶骨型为主,增强后明显强化。

Time-resolved multispectral X-ray imaging with multi-channel Kirkpatrick-Baez microscope for plasma diagnostics at Shenguang-II laser facility

A time-resolved multispectral X-ray imaging approach with new version of multi-channel Kirkpatrick- Baez （KB） microscope is developed for laser plasma diagnostics at the kilo joule-class Shenguang-II laser facility （SG-II）. The microscope uses a total external reflection mirror in the sagittal direction and an array of multilayer mirrors in the tangential direction to obtain multiple individual high-resolution, high- throughput, and quasi-monochromatic X-ray images. The time evolution of the imploded target in multiple X-ray energy bands can be acquired when coupled with an X-ray streak camera. The experimental result of the time-resolved 2.5 and 3.0 keV dual-spectral self-emission imaging of the undoped CH shell target on SG-II is given.

肺内孤立性结节的HRCT扫描与病理相关研究

目的:探讨肺内孤立性结节(Solitary pulmonary nodule,SPN)的HRCT特征与良恶性病变之间的关系。方法:对66例肺内孤立性结节病灶进行螺旋HRCT增强扫描,观察结节增强的程度、周围的血管以及瘤肺界面的特征,来判定结节的良恶性。结果:病理证实50例周围型肺癌(Peripheral lung cancer,PLC),16例良性结节。①PLC血供较良性结节丰富;②动脉期结节强化程度增强明显,平衡期达到峰值为PLC。PLC瘤肺界面清晰伴有深分叶,良性结节周围模糊。结论:PLC血供丰富、增强快,平衡期达最高,瘤肺界面清晰;良性结节增强慢,与肺界面关系模糊。