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.

嗅神经母细胞瘤的CT和MRI诊断

目的评价CT和MRI在嗅神经母细胞瘤的诊断、分期和在临床随访中的价值。资料与方法回顾性分析12例经病理证实的嗅神经母细胞瘤的CT和MRI表现,包括肿瘤部位和大小、累及范围、骨破坏、出血和坏死以及密度和信号改变等。CT平扫4例,增强扫描3例。MRI为SET1WI和T2WI,MRI平扫10例,Gd-DTPA增强扫描9例。3例有随访CT,7例有随访MRI。结果(1)肿瘤分期:按Kadish分期标准,A期0例,B期1例,C期11例,2例伴颈部淋巴结转移。(2)信号和密度改变:MRI平扫信号均匀者6例,T1WI呈低信号,T2WI呈稍高信号;信号不均匀者4例,肿瘤内可见出血和坏死区。增强扫描9例,3例为中度不均匀强化,5例为明显不均匀强化,1例为明显均匀强化。CT平扫示肿瘤密度较均匀,与肌肉接近,增强扫描2例呈中度均匀强化,1例呈明显不均匀强化。(3)沟通瘤:肿瘤同时累及颅内外者7例,双侧额叶同时受累2例,右侧额叶受累1例,左额叶受累1例,双侧额叶及左侧岛叶、基底核同时受累2例,仅累及硬脑膜者1例。脑组织水肿6例。(4)临床随访9例,影像学检查见肿物消失3例,缩小5例,术后复发1例。结论嗅神经母细胞瘤的影像学表现无特异性。检查目的为界定肿瘤累及范围。定期影像学随访有助于及时检出复发和及时行补救治疗。

嗅神经母细胞瘤的MRI诊断与评价

目的 通过分析嗅神经母细胞瘤的影像学表现 ,探讨其在临床诊断和分期中的价值。方法 经病理证实的嗅神经母细胞瘤共 18例 ,将其影像学资料进行回顾性分析 ,包括肿瘤中心位置、侵及范围、骨破坏、有无钙化、出血和积液以及信号和密度的改变等 ,并与手术结果进行对照。结果 ①肿瘤中心 :多位于上鼻腔和筛窦 ;②对于显示肿瘤侵犯的范围 ,MRI较CT更敏感 ;③肿瘤分期 :A期 0例 ,B期 2例 ,C期 16例。伴颈部淋巴结转移 6例 ,其中 1例伴颈椎及一侧睾丸转移 ;④信号和密度的改变 :T1加权像肿瘤信号均匀 ,与肌肉信号相近 ,但低于脑灰质信号 ,T2 加权像肿瘤表现为稍高或等于脑灰质信号 ,注射造影剂后呈中等或明显强化 ,多数强化不均匀。CT表现为中等较均匀密度 ,轻至中度强化。结论 MRI和CT可确定肿瘤大小、侵犯范围以及与周围血管或神经的关系 ,MRI可以多方位、多参数扫描 ,在监测治疗效果、评估预后等方面优于CT ,同时可以早期发现肿瘤复发 。

嗅神经母细胞瘤的CT诊断

目的 :探讨CT在嗅神经母细胞瘤诊断中的价值。方法 :8例嗅神经母细胞瘤 ,均经手术和病理证实 ,其中男3例 ,女 5例 ,均行冠状位和横断位CT扫描 ,平扫及增强扫描。结果 :5例肿瘤位于左侧鼻腔及左侧鼻窦 ,其中 3例侵犯左眼眶 ,1例累及颅底骨质。 3例位于双侧筛窦及鼻腔上部 ,其中 1例侵犯右额叶。平扫肿瘤的CT值为 3 5～ 44HU ,增强后肿块有明显强化。结论 :冠状位及横断位CT扫描可清晰地显示肿瘤向周围侵犯的范围 。

CT和MRI在诊断嗅神经母细胞瘤中的价值

为探讨 CT和 MRI在嗅神经母细胞瘤中的诊断价值 ,回顾性分析了 5例经 CT或 MRI检查的嗅神经母细胞瘤的临床资料和影像学表现 ,CT平扫 3例 ,其中 2例同时行增强扫描。 2例 MRI的检查序列为 SE序列 ,T1和 T2加权像 ,并用 Gd- DTPA作增强扫描。发现 5例均为 C期嗅神经母细胞瘤 ,病灶起源于鼻腔顶部 ,侵犯同侧筛窦 ,其中 4例累及同侧眼眶、蝶窦和前颅凹 ,3例侵及上颌窦。 2例 CT增强扫描为中度不均匀强化。磁共振 T1加权像上肿瘤表现为较脑组织信号低的肿块 ,T2加权像上表现为较脑组织信号高的肿块 ,病灶均匀强化。结果表明 :C期嗅神经母细胞瘤的侵犯范围广泛 ,影像学表现特异性不高 ,MRI在确定肿瘤的侵犯范围明显优于 CT,但对骨质破坏和钙化的显示不如 CT。

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。

嗅神经母细胞瘤的CT诊断

目的探讨CT在嗅神经母细胞瘤诊断中的价值。方法回顾性分析14例经病理证实的嗅神经母细胞瘤的CT资料。结果原发部位多位于鼻腔上部和筛窦;CT可清晰显示肿瘤向周围侵犯的范围;表现为中等较均匀密度,注射造影剂后呈明显强化,多数强化不均匀。结论CT可确定肿瘤原发部位、侵犯范围以及与周围血管、神经的关系,为临床治疗方案的制定提供必要的参考依据。

MRI和CT诊断嗅神经母细胞瘤的影像表现探讨

目的：探讨嗅神经母细胞瘤（esthesioneuroblastoma ，ENB）的 CT 及 MRI 影像学表现及临床特点。方法收集经病理证实的 ENB22例，分别行 CT （10／22）、MRI（12／22）扫描，分析整理并记录病灶位置、形态、强化表现、侵犯范围及 Kadish 分期等。结果22例患者平均年龄52岁（9-76岁），男14例，女8例，病变分别位于左侧鼻腔11例（11／22），右侧鼻腔9例（9／22），前颅底2例（2／22），形态规则7例（7／22），不规则15例（15／22），CT 平扫为软组织密度肿块影10例（10／22），CT 值45-58HU ，增强后3例（3／10）病灶明显强化，CT 值105-114HU 。 MRI 显示等信号软组织3例（3／12）；T1 WI 不均匀低信号9例（9／12），T2 WI 均为高信号，信号明显不均匀2例（2／12），信号均匀10例（10／12）；增强扫描呈不均匀的中等或明显强化12例（12／22）。肿瘤累及上颌骨、筛骨、鼻中隔或颅底骨质破坏16例（16／22），伴颈部淋巴结转移7例（7／22）。 A 期6例，B 期4例，C 期12例。结论 CT 及 MRI 能很好显示 ENB 影像特点及侵犯方式，并进行分期诊断。

嗅神经母细胞瘤的CT和MRI表现

目的:探讨嗅神经母细胞瘤的CT及MRI诊断价值。方法:收集资料完整的经病理证实的嗅神经母细胞瘤5例,回顾性分析嗅神经母细胞瘤的CT和MRI表现。结果:肿瘤中心均位于鼻腔顶部的中后方,形态规则1例,不规则4例。CT像上肿瘤密度多不均匀,5例邻近骨质破坏。MRI示肿瘤信号多不均匀,T1WI以等或稍低信号为主,T2WI以稍高信号为主,明显强化。肿瘤侵犯筛窦4例,眼眶2例,颅内1例。结论:嗅神经母细胞瘤多位于鼻腔顶部的中后方,强化显著,CT可清楚显示肿瘤周围骨质情况,MRI能准确显示肿瘤侵犯范围。

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.

CT和MR诊断颅内嗅神经母细胞瘤

目的探讨CT和MR诊断颅内嗅神经母细胞瘤的价值。方法收集经病理证实的15例嗅神经母细胞瘤,分别行CT和MR扫描,分析其形态、骨质改变、密度、信号及强化特点。结果本组病灶形态表现多样,3例呈圆形,4例呈椭圆形,4例呈蘑菇形,4例呈不规则形。4例病灶累及双侧筛窦、上颌窦及蝶窦,5例累及眼眶,6例累及颅底骨;10例病灶明显侵犯颅内脑实质。病灶CT均呈软组织密度影,5例病灶密度均匀,6例可见囊变区,4例可见钙化。病灶MRI表现为T2WI呈等、稍高信号,T1WI呈等、低信号,信号不均匀;当病灶侵犯脑实质可见脑内广泛水肿。增强后呈均匀或不均匀中等—明显强化。结论嗅神经母细胞瘤多数呈跨越颅内外生长,CT检查能很好地显示嗅神经母细胞瘤骨质破坏的程度,MR检查能很好地显示颅内外侵犯的范围。

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.

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.

Clinical and imaging findings in patients with severe acute respiratory syndrome

Objective To investigate the clinical and imaging characteristics of severe acute respiratory syndrome (SARS), and to study their relationship Methods Forty six SARS confirmed patients were admitted to our hospital from February to April, 2003 X ray examination documents were available in all cases and chest CT scanning was acquired in 6 cases, which were analyzed retrospectively, accompanied by their clinical features Results Fever was found in 97 8% of the patients Clinical symptoms were mild, but X ray and CT findings were distinct CT scanning demonstrated ground glass like lesions and large patchy exudation and consolidation at the early stage in 6 cases Different findings on radiography and CT were related to the different phases of the disease After treatment, most lesions were absorbed completely, but slowly in patients with multi lobe consolidation and/or extensive interstitial infiltration Conclusion Special clinical and imaging findings could be found in SARS cases The prognosis of SARS patients is related to the degree of lesions detected by radiography and CT

嗅神经母细胞瘤的CT应用评价

目的探讨ＣＴ在嗅神经母细胞瘤诊断、分期与疗后随访中的价值。方法对１３例经病理证实的嗅神经母细胞瘤ＣＴ资料结合文献进行回顾性分析。结果１３例中，１１例行术前ＣＴ检查，按Ｋａｄｉｓｈ标准分期：Ｂ期４例，Ｃ期７例。全组病灶平扫呈软组织密度，３例内部可见钙化灶，４例平扫＋增强病例，其中３例呈不均匀明显强化；６例直接增强扫描病灶密度明显高于周围软组织。４例行术后复查者，在３个月至２年内均有复发。病灶侵犯鼻腔与筛窦１３例，上颌窦１２例，蝶窦１０例，额窦２例，眼眶７例，颅内３例，颌面部２例。有４例伴有淋巴结转移。结论ＣＴ对于嗅神经母细胞瘤的术前分期与疗后尽早发现复发病灶有重要价值。病灶强化明显与侵袭性极强在此瘤的诊断中有一定特征性。

CT and MRI diagnosis of acute traumatic hepatic rupture:analysis of ten cases

In order to verify whether magnetic resonance imaging (MRI) is superior to computed tomography (CT) in the detection and characterization of intrahepatic hematoma in its acute stage, the MRI and CT features of acute traumatic hepatic rupture (ATHR) were retrospectively studied and compared. Methods: In the 10 cases of ATHR admitted to our institute, 3 were examined with CT, 1 with MRI and 6 with both CT and MRI in the first 24 hours post injury and 9 cases out of the 10 were checked up with MRI in the first week after injury of surgery. The shape of the traumatic lesions, the damages of the intrahepatic vessels and the severity of hepatic rupture displayed with CT and MRI were compared. Results: It was found that in the first 24 hours post injury, 66.6% of hepatic injuries were shown as hypointensity on T1 weighted images and low or high density on noncontrast CT. 100% of the lesions were identified as well marked hyperintensity on T2 weighted images. Damages of the hepatic and/or portal veins were observed in 7, 4 and 3 cases on T2 and T1 weighted images and noncontrast CT figures respectively. The severity of hepatic injuries were graded in 100%, 66.7% and 44.4%of cases with these 3 procedures respectively. Conclusions: On the basis of our findings, it is concluded that T2 weighted MRI is a more sensitive and reliable imaging modality in the detection and differentiation of the type and severity of acute hepatic rupture than T1 weighted imaging and noncontrast CT.