Contribution of indirect computed tomography venography to computed tomography angiography of the chest for the diagnosis of thromboembolic disease in two United States emergency departments

Summary.  Recent reports suggest that physicians in non-ambulatory settings can use indirect CT venography (CTV) of the lower extremities immediately following spiral CT angiography (CTA) of the chest to identify patients with a negative CTA who have thromboembolic disease identified on CTV. We sought to determine the frequency of isolated deep venous thrombosis (DVT) discovered on CTV in emergency department (ED) patients with complaints suggestive of pulmonary embolism (PE) yet having a negative CTA. This study was conducted in a suburban and urban ED where patients with symptoms suspicious for PE were primarily evaluated with CTA and CTV. A total of 800 patients were studied, including 360 from the suburban ED and 440 from the urban ED. 88 (11%) patients were diagnosed with thromboembolic disease by CTA, or CTV, or both. Seventy-three patients had a CTA of the chest that was positive for PE, 42 (5.2%) of whom had evidence of both PE on CTA and DVT on CTV. Fifteen patients (2%, 95% CI = 1–3%) had a negative CTA and were subsequently found to have isolated DVT on CTV, all of whom received anticoagulation therapy. These data suggest that indirect CT venography of immediately following CT angiography of the chest significantly increased the frequency of diagnosed thromboembolic disease requiring anticoagulation in ED patients with suspected PE.     

Combined computerized tomography and angiography in the diagnosis of insulinoma

We have presented a case of pancreatic insulinoma diagnosed by combined computerized tomography and angiography (CTA). In selected instances, CTA is preferable to dynamic enhanced CT in the detection of small pancreatic islet cell tumors.     

Detection of severe pulmonary hypertension based on computed tomography pulmonary angiography

The International Journal of Cardiovascular Imaging - Pulmonary hypertension (PH) is often diagnosed late in the disease course. As many patients may undergo computed tomography pulmonary...     

CT血管造影与MR血管造影对颅内动脉瘤诊断价值的对比研究

目的通过CTA检查结果与MRA检查结果的对比分析,探讨二者在诊断颅内动脉瘤中的临床应用价值。材料与方法回顾性分析60例高度怀疑颅内动脉瘤患者的DSA影像资料,及其CTA或MRA图像,在60例行DSA检查患者中,行CTA检查者30例,行MRA检查者30例。图像后处理采用最大密度投影(MIP)和容积重建(VR),以DSA检查结果及行动脉夹闭术作为诊断动脉瘤的标准,比较CTA和MRA对颅内动脉瘤的显示情况。结果在60例中,DSA和动脉瘤夹闭术共证实30个动脉瘤,其中30例16个动脉瘤CTA显示良好,30例14个动脉瘤MRA显示良好。CTA发现颅内动脉瘤的敏感性为93.3%特异性为86.7%准确性为90.0%,MRA发现颅内动脉瘤的敏感性为60.0%特异性为66.7%准确性为63.3%。结论头颈部CTA检查能够快速、安全、无创、有效的诊断脑动脉瘤,可作为临床筛查大部分颅内动脉瘤的首选检查方法。     

Use of spiral computed tomography contrast angiography and ultrasonography to exclude the diagnosis of pulmonary embolism in the emergency department

Spiral computed tomography (CT) contrast angiography is a promising imaging modality for the diagnosis of pulmonary embolism but the negative predictive value of this test remains controversial. We performed a multi-center prospective cohort study to determine the safety of relying on a negative spiral CT contrast angiography scan to exclude pulmonary embolism. Patients presenting to the Emergency Departments of three tertiary care institutions with clinically suspected pulmonary embolism were potentially eligible for the study. Patients underwent a clinical evaluation to categorize pretest probability into low, moderate, and high categories, and had D-dimer testing performed. Patients at low pretest probability with normal D-dimer were considered to have pulmonary embolism excluded. The remaining patients underwent spiral CT contrast angiography scan of the pulmonary arterial circulation and bilateral venous ultrasound of the proximal leg veins. Patients who were confirmed to have pulmonary embolism or deep vein thrombosis were treated with anticoagulant therapy. Patients in whom the diagnosis of pulmonary embolism was excluded did not receive anticoagulant therapy and were followed for a 3-month period for the development of venous thromboembolic complications. Eight hundred fifty-eight (858) patients were enrolled in this study. Three-hundred sixty-nine (369) patients had low pretest probability and negative D-dimer results and no further diagnostic tests were performed. None of these patients subsequently developed venous thromboembolic complications (0%, 95% confidence interval [CI] 0% to 1.0%). The remaining 489 were referred for spiral CT contrast angiography scan and ultrasound. Sixty-seven patients were confirmed to have pulmonary embolism and an additional 15 patients with negative CT scans had proximal deep vein thrombosis (DVT) on ultrasound for a total prevalence of venous thromboembolism of 82/489 (16.8%). Two of 409 patients who had pulmonary embolism excluded in the initial evaluation phase developed proximal venous thromboembolism (0.5%; 95% CI 0% to 1.8%) in the 3-month follow-up period. These findings suggest that the combination of a negative spiral CT contrast angiography scan and normal venous ultrasound imaging safely excludes the diagnosis of pulmonary embolism in the Emergency Department setting.     

Colonic diverticulitis diagnosed by computed tomography in the ED

The purpose of this study is to evaluate the application of computed tomography (CT) in the diagnosis of colonic diverticulitis in the emergency department (ED). Clinical information and CT images of 38 proved cases of colonic diverticulitis were reviewed retrospectively. The most common CT findings were pericolic fat infiltration (100%), thickened fascia (78.9%), muscular hypertrophy (26.3%), and arrowhead sign (23.7%). The CT findings were correlated with clinical prognosis and 3 parameters were found to be indicators for poor prognosis: older age, abscess formation, and presence of free air. The patients with diverticulitis on right side colon were found to be younger in age and the lesions were shorter in involved length with higher incidence of muscular hypertrophy and less incidence of perforation, as compared with the left side group.     

Contrast nephropathy following computed tomography angiography of the chest for pulmonary embolism in the emergency department

OBJECTIVE: To estimate the frequency of contrast nephropathy after computed tomography angiography (CTA) to rule out pulmonary embolism (PE) in the emergency department (ED) setting. METHODS: We prospectively followed patients undergoing CTA for PE, while in the ED, for 45 days. Patients who refused follow-up or were receiving hemodialysis were excluded. Severe renal failure was defined as an increase in creatinine > or = 3.0 mg dL(-1) or a need for hemodialysis within the follow-up period. Patients were also followed for laboratory-defined contrast nephropathy, defined as an increase in creatinine of > 0.5 mg dL(-1) or > 25%, within seven days following CTA. RESULTS: A total of 1224 patients were followed, and 354 [29%, 95% confidence interval (CI): 26-32%] patients had paired (preCTA and post-CTA) creatinine measurements. None developed renal failure (0/1224; 0%, CI: 0-0.3%). 44 patients developed laboratory-defined contrast nephropathy, corresponding to an overall frequency of 4% (44/1224; CI: 3-5%) and 12% (44/354; 95% CI: 9-16%) among those with paired creatinine measurements. CONCLUSIONS: Following CTA for PE, the incidence of severe renal failure was very low, but the incidence of laboratory-defined contrast nephropathy (4% overall and 12% of those with paired measurements) was higher than expected.     

Safety of ruling out acute pulmonary embolism by normal computed tomography pulmonary angiography in patients with an indication for computed tomography: systematic review and meta-analysis

Introduction : Several outcome studies have ruled out acute pulmonary embolism (PE) by normal computed tomography pulmonary angiography (CTPA). We performed a meta-analysis in order to determine the safety of this strategy in a specific group of patients with a strict indication for CTPA, that is, 'likely' or 'high' clinical probability for PE, an elevated D-dimer concentration, or both. Methods : Studies that ruled out PE by normal CTPA, with or without subsequent normal bilateral compression ultrasonography (CUS), in patients with a strict indication for CTPA, were searched for in Medline, EMBASE, Web of Science and the Cochrane dataset. The primary endpoint was the occurrence of (fatal) venous thromboembolism (VTE) in a 3-month follow-up period. Results : Three studies were identified that excluded PE by CTPA alone (2020 patients), and three studies that performed additional CUS of the legs after normal CTPA (1069 patients). The pooled incidence of VTE at 3 months was 1.2% [95% confidence interval (CI) 0.8–1.8] based on a normal CTPA result as a sole test, and 1.1% (95% CI 0.6–2.0) based on normal CTPA and negative CUS findings, resulting in negative predictive values of 98.8% (95% CI 98.2–99.2) and 98.9% (95% CI 98.0–99.4), respectively. This compares favorably with the VTE failure rate after normal pulmonary angiography (1.7%, 95% CI 1.0–2.7). The risk of fatal PE did not differ between the diagnostic strategies (0.6% vs. 0.5%). Conclusion : A normal CTPA result alone can safely exclude PE in all patients in whom CTPA is required to rule out this disease. There is no need for additional ultrasonography to rule out VTE in these patients.     

多排螺旋CT及数字减影血管造影对B型主动脉夹层评估的意义

目的探讨多排螺旋CT血管造影(CTA)和数字减影血管造影(DSA)诊断主动脉夹层(AD)的一致性及对主动脉夹层腔内修复术(TEVAR)的指导意义。方法回顾性分析资料完善的40例AD患者,比较两种方法显示的AD破口数、破口与左锁骨下动脉(LSA)的距离、左锁骨下动脉远端胸主动脉直径、主动脉夹层累及的范围及主动脉主要分支血管的累及情况、真假腔内血栓形成及钙化状况、行覆膜支架后内漏的发生率。结果两种检查方法在检测AD破口数、破口距LSA的距离、胸主动脉直径方面差异无统计学意义。CTA、DSA发现夹层累及左、右侧髂动脉平面的例数分别为16例(40.0%)、6例(15.0%)和15例(37.5%)、6例(15.0%),两种方法在检测夹层累及左、右侧髂动脉平面时的准确度差异均有统计学意义(P<0.05)。CTA可检测出夹层血栓、动脉壁钙化,而DSA无法显示。40例AD患者行TEVAR 34例,覆膜支架置入后DSA即刻检测发现内漏者11例(32.4%)。结论 CTA、DSA两者对诊断AD有较好的一致性,对TEVAR术前、后有指导价值。     

双源CT大螺距扫描联合迭代重建在肺动脉成像中的应用研究

目的：探讨双源CT大螺距（Flash）模式结合迭代重建（SAFIRE）在肺动脉成像中降低辐射剂量、优化图像质量的价值。方法：收集临床疑诊肺动脉栓塞需行CTPA检查、无检查禁忌症的患者60例,每组20例,分别接受不同的扫描模式;由两名放射科医师对图像用5分法进行主观评估,并测量7个肺血管CT值（HU±SD）,并计算信号噪声比（SNR）和对比信噪比（CNR）,比较辐射曝光参数,包括CT容积剂量指数（CTDIvol）和剂量长度乘积（DLP）,并计算有效辐射剂量（ED）;使用SPSS16．0统计软件对数据进行分析。结果：所有图像均满足诊断要求,3种方案的影像质量在主观评价及客观测量（SNR、CNR）方面均无显著差异（P〉0．05）,而辐射剂量在不同方案之间不同,实验组2的辐射剂量（CTDvol和DLP）明显低于对照组及实验组1,差异具有统计学意义（P〈0．001）。结论：联合应用SAFIRE及Flash扫描模式行CTPA检查时可以在满足图像诊断要求前提下进一步降低辐射剂量。     

Computed tomography pulmonary angiography in the diagnosis of acute pulmonary embolism in the emergency department

This study was undertaken to evaluate the use of computed tomography pulmonary angiography (CTPA) in patients with pulmonary embolism (PE) who were followed in the emergency department (ED). The files and computer records of 850 patients older than 16 years of age who were seen in the Hacettepe University Hospital ED between April 10, 2001, and December 1, 2005, and who required CTPA for PE prediagnosis and/or another diagnosis, were studied retrospectively. PE was identified by CTPA in 9.4% of 416 women and in 5.8% of 434 men. A significant difference (P< .05) was noted in the women and men in whom PE was detected. The mean age of the patients was 58.13±17.88 y (range, 16–100 y). Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for clinical susceptibility to PE among patients who underwent CTPA were assessed at 95.3%, 48.2%, 13%, and 99.2%, respectively. CTPA was done for different reasons: aortic aneurysm dissection (n=1), cough distinctive diagnosis (n=1), dyspnea distinctive diagnosis (n=6), chest pain distinctive diagnosis (n=3), PE prediagnosis (n=51), and other reasons (n=2). Also, sensitivity, specificity, PPV, and NPV were found to be 95.4%, 16.2%, 14.4%, and 96%, respectively, for D-dimer. CTPA, which is accessible on a 24-h basis in the ED, is a valuable tool for the diagnosis of PE.     

Intravenous contrast alone vs intravenous and oral contrast computed tomography for the diagnosis of appendicitis in adult ED patients

Objective

When the diagnosis of appendicitis is uncertain, computerized tomography (CT) scans are frequently ordered. Oral contrast is often used but is time consuming and of questionable benefit. This study compared CT with intravenous contrast alone (IV) to CT with IV and oral contrast (IVO) in adult patients with suspected appendicitis.

Methods

This is a prospective, randomized study conducted in a community teaching emergency department (ED). Patients with suspected appendicitis were randomized to IV or IVO CT. Scans were read independently by 2 designated study radiologists blinded to the clinical outcome. Surgical pathology was used to confirm appendicitis in patients who went to the operating room (OR). Discharged patients were followed up via telephone. The primary outcome measure was the diagnosis of appendicitis. Secondary measures included time from triage to ED disposition and triage to OR.

Results

Both IV (n = 114) and IVO (n = 113) scans had 100% sensitivity (95% confidence interval [CI], 89.3-100 and 87.4-100, respectively) and negative predictive value (95% CI, 93.7-100 and 93.9-100, respectively) for appendicitis. Specificity of IV and IVO scans was 98.6 and 94.9 (95% CI, 91.6-99.9 and 86.9-98.4, respectively), respectively, with positive predictive values of 97.6 and 89.5 (95% CI, 85.9-99.9 and 74.2-96.6). Median times to ED disposition and OR were 1 hour and 31 minutes (P < .0001) and 1 hour and 10 minutes (P = .089) faster for the IV group, respectively. Patients with negative IV scans were discharged nearly 2 hours faster (P = .001).

Conclusions

Computerized tomography scans with intravenous contrast alone have comparable diagnostic performance to IVO scans for appendicitis in adults. Patients receiving IV scans are discharged from the ED faster than those receiving IVO scans.     

ED utilization of computed tomography in a poisoned population

The objective of this prospective, analytic study was to identify predictors and describe the demographic and clinical correlates of head computed tomography (CT) evaluation in patients with poisoning or drug overdose and altered mental status. Forty-three patients that were evaluated by head CT and 109 that were not evaluated by head CT were entered into the study at a poison control center. None of the 43 scanned patients had any acute findings on head CT. A logistic regression model yielded 4 predictors that were statistically associated with the ordering of a head CT scan: Glasgow Coma Scale (GCS) < or = 8 (odds ratio [OR]: 2.3; 95% confidence interval [CI] 1.03-5.7); age > or = 41 years (OR 5.3; 95% CI 2.2-13); use of drugs or abuse by history (OR 2.8; 95% CI 1.04-7.6); and witnessed seizure activity (OR 4.8; 95% CI 1.3-17.9). We also tested 2 additional models to identify predictors of hospital admission, 1 with and 1 without CT scan included as a covariate. In the first model, only GCS 相似文献   

Subjective assessment of right ventricle enlargement from computed tomography pulmonary angiography images

To retrospectively evaluate prognostic accuracy of subjective assessment of right ventricle (RV) enlargement on CT pulmonary angiography (CTPA) images in comparison with objective measures of RV enlargement in patients with acute pulmonary embolism (PE). For 200 consecutive patients with acute PE, two readers blinded to patient outcomes subjectively determined whether the maximum RV diameter was greater than that of the left ventricle (LV) using axial CTPA images. For the objective measurements, RV/LV diameter ratios were calculated using axial images and 4-chamber reformatted images. For all assessments, sensitivities and specificities for predicting PE-related death within 30-days and a composite outcome including PE-related death or the need for intensive therapies were compared. The agreement between two readers was 91.5% (kappa = 0.83) and all other assessments had pair-wise agreement over 75% (kappa = 0.53–0.72). There was no significant difference in sensitivity between the subjective and objective methods for predicting both outcomes. The specificity for subjective RV enlargement (55.4–67.7%) was significantly higher than objective measures (45.8–53.1%), except for the 4-chamber views where, for one reader, the specificity of the subjective evaluation was higher but did not reach statistical significance. Complex measurements of RV/LV diameter ratios may not be needed to maximize the prognostic value from CTPA. The radiologist who interprets the CTPA images should report RV enlargement when the RV diameter subjectively appears larger than the LV.     

Helical computed tomography and alternative diagnosis in patients with excluded pulmonary embolism

OBJECTIVE: A clinical diagnosis of pulmonary embolism (PE) is confirmed objectively in 20-30% of patients. Helical computed tomography (CT) can allow an alternative diagnosis to be made. The frequency and validity of alternative diagnoses on helical CT in consecutive patients presenting with clinically suspected PE was assessed. PATIENTS AND METHODS: In all 512 prospectively analyzed patients helical CT scan was performed, and apart from presence or absence of PE, pathologic changes in lung parenchyma, mediastinum, cardiovascular system, pleura and skeleton were recorded. When possible an alternative diagnosis was given and compared with the final diagnosis after 3 months follow-up. RESULTS: In 130 patients (25.4%) PE was excluded and an alternative diagnosis considered likely. In 123 of the 130 patients (94.6%) this diagnosis was unchanged at 3 months follow-up. The diagnoses included pneumonia (n = 67), malignancy (n = 22), pleural fluid (n = 10), cardiac failure (n = 10), COPD (n = 6) and a variety of other causes (n = 15). The diagnosis changed at follow-up in seven patients (5.4%). An initial diagnosis of pneumonia changed to malignancy in two patients and to pleuritis and cardiac failure in one patient each. In two other patients malignancy and chronic obstructive pulmonary disease (COPD) were ruled out and the diagnosis changed to pneumonia. In one patient the final diagnosis remained unknown after an initial suspicion of malignancy. CONCLUSION: In clinically suspected PE helical CT allows a reliable alternative diagnosis to be made in 25.4% of patients. This feature is an unique advantage in comparison with other diagnostic tests and supports the decision of taking helical CT as first line test in suspected PE.