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.

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.

双低剂量CTU在非结石性上尿路梗阻诊断中的应用价值

目的探讨低对比剂浓度、低管电压方案CTU在非结石性上尿路梗阻诊断中的应用价值。方法选取经CT平扫及超声检查提示上尿路梗阻且梗阻原因排除结石性上尿路梗阻患者52例,所有患者均在我院行双源CT低浓度、低管电压CTU且CT平扫与CTU检查时间间隔7天以内,对获得的图像在Syngo.via后处理工作站进行图像重建及分析,将分析结果与病理结果或临床最终诊断结果进行对比分析,评价双低剂量CTU在非结石性上尿路诊断有效性。结果52例上尿路梗阻原因均得到明确诊断,其中19例为先天发育异常所致,17例为内源性肿瘤所致,6例为外源性肿瘤压迫所致,10例为炎性病变所致。结论CT双低剂量CTU所获得图像质量能够满足非结石性上尿路梗阻诊断需求,并可以显著降低对比剂剂量及辐射剂量。

直接法多层螺旋CT静脉造影在下肢深静脉血栓中的价值

目的探讨直接法多层螺旋CT静脉造影(MSCTV)在下肢深静脉血栓中的临床应用价值。方法对临床高度怀疑下肢深静脉血栓疾病的27例患者采用不同注射速率进行直接法MSCTV,所有采集的原始数据导入Wizad高级后处理工作站,经最大密度投影(MIP)、多平面重组(MPR)和容积再现法(VR)重建,分阶段对比分析图像质量,并与24例行DSA下肢深静脉造影的门诊患者进行分阶段静脉显示能力对比分析。结果①所有受检者血管重建显示良好,24例可显示不同部位、不同程度深静脉血栓形成,表现原始轴位图上血管腔内的充盈缺损,重建图像上显示管腔狭窄、中断或变细,明显浅静脉、侧支静脉扩张、纡曲。②采用不同注射速率进行直接法MSCTV在下肢深静脉血栓图像质量显示方面差异具有显著性,直接法MSCTV与DSA下肢静脉造影对腓肠静脉、腘静脉和股静脉的显示能力相同(χ2=1.021,P=0.312),直接法MSCTV显示髂静脉的能力优于DSA下肢静脉造影(χ2=4.364,P=0.037)。结论直接法MSCTV在下肢深静脉血栓中具有重要应用价值,显示不同节段静脉需要不同的注射速率。

茎突舌骨韧带骨化致茎突综合征治愈分析

茎突综合征是1937年Eagle提出的因茎突过长和（或）方位、形态异常导致的周围血管、神经或其他组织受刺激引起的咽部不适，包括咽部异物感、咽痛、反射性耳痛及头颈痛等症状的一组综合征。临床上由于茎突过长或者方位异常引起的茎突综合征并不少见，但由于茎突舌骨韧带骨化致茎突综合征并不多见，现报道如下。

脑静脉与静脉窦血栓形成的影像学研究

目的回顾性分析34例颅内静脉与静脉窦血栓形成(CVST)病例的CT、MRI资料,探讨CVST的起源部位、发展延伸和分布规律以及血栓与脑实质病变之间的联系。资料与方法统计静脉窦血栓的累及部位,并以SE序列矢状位T1WI血栓的早期信号演变为依据,推断受累的先后顺序。比较血栓累及上矢状窦和侧窦时与单纯侧窦血栓时脑实质病变的差异。统计学方法为四格表资料的Fisher确切概率检验。结果静脉窦血栓多为连续性分布累及多个静脉窦或在一个静脉窦内呈空间连续性分布,常为全程上矢状窦经窦汇与至少一侧侧窦同时受累,此时早期T1WI上矢状窦常最早出现高信号。血栓累及上矢状窦、侧窦与单纯侧窦血栓时颞枕叶脑实质病变的发生率不同,P值≈0.0004。结论静脉窦血栓多为连续性分布累及多个静脉窦或在一个静脉窦内呈空间连续性分布,上矢状窦常最先受累。血栓常顺血流方向延伸,首先发生血栓的部位容易造成脑实质损害,而延伸累及的部位不易造成脑实质损害。

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。

CT引导下肺内单发结节带钩钢丝穿刺定位并发症分析

目的探讨CT引导下单发肺结节带钩钢丝穿刺定位并发症发生率及影响因素.方法收集48例肺内单发结节需要行CT引导下带钩钢丝穿刺定位患者的临床资料,分析穿刺结果及并发症情况,将影响因素通过χ^2检验进行统计学分析.结果48例患者均获得满意的定位,定位后出现并发症31例,其中肺内和针道出血18例(37.5%),气胸13例(27%),轻微咳血2例.χ^2检验结果显示,穿刺次数、穿刺距离与并发症的发生率有显著的关系(P<0.05).结论CT引导下肺内单发结节带钩钢丝穿刺是胸腔镜术前重要的定位方式,减少穿刺次数和选择短的穿刺距离对降低并发症、提高定位成功率具有重要临床意义.

腹部CT在医源性结肠镜穿孔诊断中的应用价值

目的探讨腹部CT检查在医源性结肠镜穿孔(ICP)预防、诊断和治疗选择的重要性。方法回顾性分析2017年1月至2019年12月15例ICP患者的临床和CT影像资料。结果结肠镜术前CT检查8例,发现高危因素6例,鈷肠明显梗阻性扩张、乙状结肠迂曲冗长各2例乙状结肠多发憩室、结肠肠壁广泛轻度炎性水肿各1例。结肠镜术后CT检查15例,诊断腹腔内穿孔7例,腹膜后穿孔6例,累及腹膜腔内外穿孔2例。穿孔部位:升结肠4例、横结肠2例、降结肠2例、降结肠乙状结肠交界部1例、乙状结肠3例、直肠3例。内科保中治疗8例,外科手术治疗5例。钛夹夹闭1例,死亡1例。结论腹部CT检查有助于结肠镜术前发现高危因素,预防ICP的发生,结肠镜术后尽早确诊ICP,并为临床后续治疗方式的选择提供关键依据。

纵隔型肺癌的CT表现分析

目的:分析纵隔型肺癌的CT表现特征,提高对纵隔型肺癌的认识,减少误诊。材料和方法:收集11例经手术或纤支镜及病理证实的纵隔型肺癌的CT扫描资料,着重分析肿块的位置、大小、边缘特征、肺内改变,以及与纵隔的关系。结果:11例纵隔型肺癌的肿块紧贴纵隔生长或大部分位于纵隔内,多呈类圆形或椭圆形。6例位于上纵隔,3例位于中纵隔,9例位于前、中纵隔边缘。邻近支气管常有狭窄或闭塞。8例短毛刺,10例分叶,5例原发癌肿与肺门及纵隔肿大淋巴结融合成块。11例肺癌中,小细胞癌6例。结论:纵隔型肺癌生长大多与纵隔密切相关,但仍具有肺癌的CT表现特征。

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.

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.

颅内环状强化病变的影像学的表现与分析

目的提高颅内环状强化病变的诊断水平。方法追踪观察164例CT、MRI影像呈环状强化的病例,在解剖分布、数目、囊壁的形态及周围组织内的间接征像等进行比较和分析。结果脑脓肿、胶质瘤、转移瘤、脑结核瘤、脑囊虫病等12种疾病可见环状强化表现,并各有其特点。结论脑脓肿和转移瘤多分布于皮髓交界处,脑内环状强化病变的影像学表现形式,可为诊断及鉴别诊断提供重要依据。

CT-GUIDED PERCUTANEOUS TRANSTHORACIC FINENEEDLE ASPIRATION BIOPSY OF SMALL PERIPHERAL PULMONARY LESIONS

CT guided percutaneous transthoracic fine needle aspiration biopsy (PTFNAB) was performed in twenty four sputum negative cases of small peripheral pulmonary lesions smaller than 2 cm in diameter, which are not easily diagnosed or accessible to fibrobron choscopes. After thin slide scanning and localization with Somatom DR H computed tomography, pulmonary nodules were biopsied with a 20 Gauge needle guided by a ruler specially designed. Biopsy materials were used for cyto and histopathologic examinations. The diagnosis accuracy of biopsy was evaluated by the result of postoperative pathology and/or follow up for 2 years. Sixteen pulmonary lesions were proved to be malignant and 8 were benign. The sensitivity was 75.0% (12/16), speciti vity 100% (8/8) and accuracy 83.3% (20/24) according to cytopathology and 87.5% (14/16), 100% (8/8), 91.7% (22/24) by histopathology, respectively. Two cases of early stage peripheral lung cancer were detected and proved by operation. CT guided PTFNAB is safe and quick for diagnosis with high accuracy for small peripheral pulmonary lesions which are usually negative in sputum examination and bronchoscopy. PTFNAB should be routinely used in the diagnosis of lung neoplasms.

CT Manifestations of Lung Changes and Complications in Patients with Severe Acute Respiratory Syndrome

Objective:To investigate the rol e of CT scanning in diagnosing severe acute respiratory syndrome(SARS). Methods: One hundred and twelve times of spiral CT scanning, 106 t imes on the chest with standard pulmonary and mediastinal window, 5 on the brain and once on the abdomen, were performed in 82 patients (37 males and 45 females ) of SARS. Results: Bilateral shadows showed in 66 patients (80.48%) and unil ateral shadow in 16 (19.52%). The lung CT findings were sub pleural focal con solidation in 26 patients (31.70%), flaky cloudy opacity in 53 (64.63%), large a rea consolidation in 9 (10.97%), ground glass blurry shadow in 31 (37.80%), a lveolar substantive shadow in 14 (17.07%) and interstitial changes in 16 (19.51% ). The pulmonary CT signs of SARS were relatively characterized by: (1) The lesi ons tending to multiply occur, mostly to be bilaterally distributed and commonly involved in the lower lung field. (2) The lung shadows mostly showed as sub pleural focal consolidation, flaky cloudy shadow, large area consolidation, grou nd glass blurry shadow, and often accompanied with signs of broncho inflat ion. (3) Having opacified nodular shadows in the alveolar cavities. (4) Rapid pr ogressions or changes on the size, amount, and distribution of the lesions likel y to be found in dynamic observation of chest X ray and CT scanning, i.e., ma rkedly dynamic changes found within 24 to 48 hrs. Lesions with these characteris tics may be recognized as pulmonary changes possibly induced by SARS. Complicati ons were found in 6 patients (7.31%), including tuberculosis of lung and brain a ccompanied with pneumomediastinum in one patient, secondary infection of lung in 2, pneumothorax in 1, pulmonary fungus in 1, and pyothorax in 1.Conclusion: CT scanning is a sensitive method for diagnosis of SAR S, by which more accurate assessment of the abnormal changes of lung and occurre nce of complications in SARS patients can be made.

A comparative study on CT imaging and pathologic presentation of the periphery of hepatocellular carcinoma using in vivo specimens of liver transplantation

Objective:To examine CT and pathologic presentations of the periphery of hepatocelllar carcinoma (HCC) by using in vivo liver specimens from orthotopic liver transplantation (OLT) and to see whether there is any correlation between them. Materials and Methods:Forty-two patients with HCC confirmed by pathology and liver transplantation were included. Plain CT scan covering the whole liver was done, followed by arterial and portal venous phase scanning. The delay time was 25 s and 60 s after injection of contrast medium. Fresh liver samples were evaluated, sliced and stained with HE and the standard immunoperoxidase method using facterⅧrelated antigen (F8RA) monoclonal antibody to study CT presentation of the periphery of tumor and compare them with pathologic findings. Results: (1) Tumors with clear boundaries on CT scan reflected the presence of tumor capsules in pathologic sections. Most tumors with unclear boundaries had no capsules and grew in an invasive pattern; (2) Tumors with unclear boundaries or high density on dynamic enhancement usually had abundant newborn vessels in the periphery and were poorly differentiated, while those with low density had few newborn vessels and were well differentiated; (3) When microvessel density (MVD) was>30, the occurrence of intrahepatic daughter foci was higher. Conclusion: (1) CT morphologic classification of the HCC periphery can well reflect the intactness of tumor capsules, which is helpful for preoperative assessment of tumor infiltration and cancer cell grading; (2) CT enhancement presentation of the HCC periphery in arterial and portal phases may reflect pathologic changes and help predict the prognosis at large.

肝癌引起门脉癌栓40例影像学分析

对Ｂ超诊断为门脉癌栓的４０例患者进行ＣＴ扫描，在增强后扫描，门脉内显示出底密度缺损影；门脉主干增宽；腹水及脾肿大；癌灶呈播散性；１９例主癌灶位于肝方叶邻近；仅少数病例出现肝外转移。

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.