The correlation of the D-dimer test and biphasic computed tomography with mesenteric computed tomography angiography in the diagnosis of acute mesenteric ischemia

Background

Early diagnosis is the main factor to improve the outcome of acute mesenteric ischemia (AMI). The goal of this study was to assess the correlation of the D-dimer test and biphasic computed tomography (CT) with mesenteric CT angiography for the diagnosis of AMI.

Methods

Selected consecutive patients with a clinical suspicion of AMI were admitted to the study. Blood samples were taken before biphasic CT with mesenteric CT angiography examination.

Results

The sensitivity and specificity values of biphasic CT with mesenteric CT angiography were 92.9% and 89.5%, respectively. The sensitivity and specificity of D-dimer testing for the diagnosis of AMI were 94.7% and 78.6%, respectively. D-dimer levels higher than 3.17 μg fibrinogen equivalent units/mL were more specific (P < .0001) and acted similarly to the biphasic CT with mesenteric CT angiography in the diagnosis of AMI.

Conclusions

In the setting of early diagnosis of AMI, the D-dimer test may improve our ability to diagnose patients in whom we cannot use multidetector row CT with CT angiography.     

CT血管造影技术在枕颈手术中的应用

目的 评价在枕颈手术中应用术前CT血管造影(CTA)技术的价值.方法 16例枕颈疾病患者在术前进行CTA检查.完成3D重建后,评价椎动脉寰枢段走行、分支.测定寰椎椎动脉沟距中线距离、侧块中点距中线距离、枢椎峡部宽度等指标.根据影像学研究进行后路枕颈固定2例,后路寰枢固定10例,经口1例,经口 枕颈固定2例,单纯减压手术1例.结果 影像学研究发现椎动脉不对称3例,异常分支2例, 直接入颅1例, 肿瘤侵犯1例.16例手术均未出现医源性椎动脉及脊髓损伤.结论 在枕颈部畸形及肿瘤患者存在很高的椎动脉异常发生率,CTA是进行枕颈部手术前一项很有价值的检查,降低了损伤椎动脉的发生率.     

Diagnosis of cavernous haemangiomas by computed tomography and angiography

Summary Computed tomography and angiographical findings of cavernous haemangiomas of the brain are reported on the basis of six cases of the authors, and a review of the literature. Computed tomography showed well demarcated, round densities with tiny calcifications, and mild contrast enhancement (0-25 HU), with no mass effect and with open sulci round the lesion. The angiographical findings were normal except in one patient with an early draining vein and in another with a late draining vein; consequently an injection of at least 10 to 15 ml of contrast medium, and a prolonged angiographical series are recommended. According to the literature, capillary blush may also be seen in angiography. If both CT and angiography are used the diagnosis is definitive, and a neoplasm can be excluded. In five of our patients the diagnosis was verified surgically and histologically, while the sixth patient was not operated on because the frontoparietal lesion was near the motor region. In most cases, surgical removal is easy and successful.     

64排螺旋CT冠状动脉成像误诊分析

目的对照X线冠状动脉造影分析64排螺旋CT冠状动脉成像误诊原因。方法搜集140例患者64排螺旋CT冠状动脉成像（64DCTCA）完整资料,以其近期实施的X线冠状动脉造影（CAG）结果为金标准对比,对于两种检查结果中不同的部分进行分析。结果本组64DCTCA显示1343支冠状动脉,不同部位的Ⅲ级血管冠状动脉成像质量无显著差异（χ^2检验,P〉0.05）。在Ⅰ、Ⅱ级血管中,79支两项检查结果不一致,其中64DCTCA假阳性28支,假阴性14支,10支病变程度评估过重,27支评估过轻。各组血管间总体存在显著差异（χ^2检验,P〈0.01）;对冠状动脉主干与分支的误诊率之间存在显著差异（χ^2检验,P〈0.01）,而冠状动脉主干LAD,LCX和RCA病变显示无显著差异（χ^2检验,P〉0.05）。结论完善的检查前准备是保障64DCTCA重组优质冠状动脉图像的前提,良好的图像后处理有助于避免误诊。     

彩超及CTA对胡桃夹综合征的诊断价值

目的探讨彩超及CTA对胡桃夹综合征（NCS）的诊断价值。方法分析50例NCS患者及50例健康人的资料。结果主诉肉眼及镜下血尿31例;疲乏伴纳差4例;左精索静脉曲张10例;蛋白尿伴左腰不适5例。13例女性有盆底淤血征,男性均有不同程度左精索静脉曲张。彩超肠系膜上动脉（SMA）和腹主动脉（AO）夹角（a）（25.08±11.83）°vs.（48.73±25.82）°;左肾静脉（LRV）受压管径（D1）（2.45±1.28）vs.（3.48±1.02）cm,血流速度（V1）（0.38±0.16）vs.（0.48±0.13）m/s;LRV远端管径（D2）（8.55±2.63）vs.（7.43±2.03）cm,血流速度（V2）（0.28±0.21）vs.（0.94±0.43）m/s。21例CTA示SMA与AO夹角减小,1例示胰头部压迫,3例SMA分支及下方纤维结构压迫;1例后胡桃夹征（腹主动脉和脊柱之间压迫）,15例膀胱镜左输尿管口喷血。结论彩超初步筛选胡桃夹征,CTA更清晰显示LRV周围结构。     

多层螺旋CT血管造影技术在穿支皮瓣修复下肢软组织缺损中的应用

目的 探讨应用多层螺旋CT血管造影(MDCTA)进行术前穿支血管特征评估、指导“freestyle”穿支皮瓣临床应用的效果.方法 2011年2月至2012年12月,对下肢软组织缺损40例术前均采用MDCTA行穿支评估,包括位置、口径、走行、与邻近结构的关系.选择优势穿支设计不同的穿支皮瓣进行软组织修复重建,并评估术前与术中穿支位置的吻合率. 结果 应用带蒂螺旋桨穿支皮瓣19例,游离穿支皮瓣21例.术后所有皮瓣均存活,仅1例膝降动脉穿支皮瓣远端出现2 cm×2 cm的坏死,经换药后治愈.供区37例直接关闭缝合,3例通过部分植皮.术前穿支定位与术中所见穿支位置吻合率为97.5％.结论 术前MDCTA可以提供准确的穿支解剖学特征信息,在下肢软组织修复重建时,皮瓣的设计更具随意和准确,手术更加简单、安全,从而减少了供区损伤并获得最佳的修复效果.     

多层螺旋CT血管成像在烟雾病诊断中的应用

目的探讨多层螺旋CT血管成像（MSCTA）在烟雾病诊断中的价值以及应用前景。方法回顾性分析10例烟雾病患者的MSCTA及数字减影血管造影（DSA）的影像学资料。结果MSCTA可清晰显示狭窄、闭塞以及异常增多的脑血管。容积重建有利于显示病变血管与周围结构的空间关系,综合最大密度投影法重建和多曲面重建图像分析可清晰显示异常增多的脑血管,即烟雾状血管。MSCTA对狭窄及闭塞血管的检出率为66．2％（53/80）;DSA对狭窄及闭塞血管的检出率为67．5％（54／80）,两者比较差异无统计学意义（P〉0．05）。MSCTA对颅底异常血管网的显示及分布情况与DSA大致相似。结论MSCTA诊断烟雾病的灵敏度高,是早期诊断烟雾病的重要依据,早期诊断、及时治疗是改善烟雾病患者预后的有效方法。     

A systematic review of whether oral contrast is necessary for the computed tomography diagnosis of appendicitis in adults

BACKGROUND: There are several methods of contrast administration when performing computed tomography (CT) scanning for suspected appendicitis. In this systematic review we evaluated the diagnostic performance of CT with and without contrast material. METHODS: Twenty-three reports were identified using a Medline search. RESULTS: The aggregated diagnostic performance characteristics of all modes of CT scanning were excellent with a range of sensitivity (83--97%), specificity (93--98%), positive predictive value (86--98%), negative predictive value (94--99%), and accuracy (92--97%). The diagnostic performance of CT without oral contrast was similar (sensitivity, 95% vs. 92% [not statistically significant]; negative predictive value, 96% for both protocols) or surprisingly better (specificity, 97% vs. 94%; positive predictive value, 97% vs. 89%; accuracy, 96% vs. 92%; P<.0001) than with oral contrast. CONCLUSIONS: Noncontrast CT techniques to diagnose appendicitis showed equivalent or better diagnostic performance compared with CT scanning with oral contrast. A prospective comparative trial of CT with and without oral contrast for appendicitis should be performed to assess the adequacy of this modality.     

Patient selection essential for computed tomography coronary angiography

Objective: Computed tomography coronary angiography (CTCA) has become a commonly used imaging modality in patients with suspected anginal symptoms but also in asymptomatic populations. This practice has raised concerns due to potential high radiation exposure in terms of adequate benefit to risk profile.

Design: Demographics and CTCA scan details were collected from a consecutive series of 586 patients referred to a single community radiology practice for a CTCA.

Results: Of the 586 patients, 271 (46.2%) were women. Mean age was 58.3 standard deviation (SD) 12.2, range 15–90 years, body mass index (BMI) 28.6 SD 5.9?kg/m², and heart rate 60 SD 10 beats per minute. Mean total radiation was 4.79 SD 3.45 mSv (range 0.64–31.34). The mean radiation exposure in the lowest quartile of BMI and heart rate were 3.01 SD 1.84 mSv and 3.95 SD 2.72 mSv, compared to the highest 7.32 SD 3.51 mSv and 6.20 SD 4.38 mSv (p for trend <0.0001 in both).

Conclusion: The radiation exposure in this consecutive series of patients is low in general but patient selection for CTCA imaging appears to be paramount. Patients with a high BMI and especially with high heart rate receive a higher dose of radiation.     

Intravenous digital subtraction angiography and helical computed tomography in evaluation of living renal donors

OBJECTIVES: The present study was carried out to evaluate the accuracy of helical computed tomography (CT) and intravenous digital subtraction angiography (IV-DSA) on anatomical assessment of renal vasculature for living renal donors. METHODS: Forty-two healthy potential renal donors were prospectively evaluated and 35 subsequently underwent donor nephrectomy after helical CT and IV-DSA evaluation. The vascular and non-vascular findings were compared between the findings on helical CT, IV-DSA and surgery. RESULTS: Ten prehilar branches and five accessory renal arteries were found at nephrectomy. Overall, operative findings agreed with the findings by IV-DSA in 89% and by helical CT in 83%. In delineating accessory arteries, IV-DSA had a sensitivity of 60% and specificity of 97%, whereas helical CT had a sensitivity of 40% and specificity of 100%. In delineating prehilar branches, IV-DSA had a sensitivity of 90% and specificity of 100%, whereas helical CT had a sensitivity of 70% and specificity of 100%. Accessory arteries and prehilar branches that were not detected by helical CT or IV-DSA, were less than 2 mm in diameter and did not require vascular reconstruction. Renal veins were delineated in 63% by IV-DSA, whereas they were clearly imaged by helical CT in all cases, including a case with a circumaortic renal vein. Non-vascular findings were obtained in 64% by helical CT, including two renal tumors. None of these findings were obtained by IV-DSA. CONCLUSION: Helical CT and IV-DSA provide comparably sufficient information on renal artery vasculature. However, helical CT provides significantly more information on venous and non-vascular findings as a single-imaging modality.     

Comparison of multislice computed tomography angiography and digital subtraction angiography in the detection of residual or recurrent aneurysm after surgical clipping with titanium clips

Purpose  To determine the diagnostic accuracy of 3D-CTA using volume rendering (VR) in the detection of residual or recurrent cerebral aneurysms after clipping. Material and methods  Between January 2006 and November 2007, 45 patients (20 female, 25 male) with 50 intracranial aneurysms treated using titanium clips were enrolled in this study. IADSA and 3D-CTA were performed within 1 month after surgery in 27 (60%) patients, after 1 year in 12 (26%) patients and after 5 years in six (13%) patients. In blinded fashion, CTA and DSA images were independently interpreted by two senior neuroradiologists with 7 years of experience in vascular diagnostic neuroradiology. The diagnostic performance of MDCTA compared with DSA for the detection of aneurysm remnants was measured by receiver operating characteristic (ROC) analysis. The area under the ROC curve, 95% confidence interval (CI), sensitivity, and specificity were calculated. Results  For the detection of residue–recurrent aneurysm; the sensitivity and specificity of MDCTA were 87.5% (95% CI = 52.9–97.8%) and 97.4% (95% CI = 86.5–99.5%) for the first reader and 87.5% (95% CI = 52.9–97.8%) and 100% (95% CI = 90.8–100%) for the second reader respectively. Receiver operating characteristic (ROC) analysis revealed good diagnostic performance for 3D-CTA (mean area under ROC curve (Az) = 0.98 and 0.99 for the first and the second observer, respectively) The kappa values extracted from the interobserver concordance analysis for agreement observers regarding the use of MDCTA for assessment of a remnant neck was 0.62. Conclusion  Using MDCTA, it is possible to demonstrate the status of intracranial aneurysms after surgical clipping in the immediate postoperative period as well as long-term follow-up with an high sensitivity and specificity when comparing with the findings of DSA.     

Digital subtraction angiography and dynamic computed tomography for evaluating the hemodynamics in cases of giant intracranial aneurysm

Dynamic computed tomography (CT) and digital subtraction angiography were used for postoperative evaluation of the hemodynamic changes in five patients with giant or large intracranial aneurysms. The lesions in four of these cases were giant or large aneurysms of the internal carotid artery, and were treated by occlusion of the cervical internal carotid artery and superficial temporal-middle cerebral artery anastomosis. The lesion in the fifth case was a giant aneurysm of the right vertebral artery, which was treated by proximal clipping of the vertebral artery. Preoperative digital subtraction angiography revealed aneurysmal staining, and dynamic CT scanning indicated the rapid transit of contrast medium in the dome of the aneurysm. Dynamic CT scanning immediately after operation indicated a low flow state in all of the aneurysms, suggesting that they were thrombosed. Although within a few months the peripheral edges of the aneurysms became enhanced, dynamic CT scanning revealed a slower transit of contrast medium through the centers of the aneurysms than in the basilar artery, and digital subtraction angiography failed to demonstrate aneurysmal staining, suggesting that the aneurysms remained thrombosed. The present data indicate that dynamic CT scanning and digital subtraction angiography may be useful for relatively noninvasive evaluation of the hemodynamic changes in patients with giant intracranial aneurysms.     

Clinical implementation of coronary computed tomography angiography for routine detection of cardiac allograft vasculopathy in heart transplant patients

Cardiac allograft vasculopathy (CAV) is an accelerated form of coronary artery disease that affects long-term outcomes in heart transplant (HTx) patients. We prospectively evaluated the feasibility of coronary computed tomography angiography (CCTA) for the detection of CAV during clinical implementation at our center. All consecutive HTx patients >4 years post-transplant were actively converted from myocardial perfusion imaging to CCTA for the annual assessment of CAV. Between February 2018 and May 2019, 129/172 (75%) HTx patients underwent a CCTA. Renal impairment (n = 21/43) was the most frequent reason for patients could not undergo CCTA. CCTA image quality was good–excellent in 118/129 (92%) patients, and the radiation dose was 2.1 (1.6–2.8) mSv. CCTA showed obstructive CAV in 19/129 (15%) patients. Thirteen (10%) patients underwent additional tests, of which 8 patients underwent coronary revascularization within 90 days of CCTA. After 1 year, 3 additional coronary angiograms were performed, resulting in one revascularization in a patient with known severe CAV who developed ventricular tachycardia. One myocardial infarction after coronary stenting and 2 non-cardiac deaths were observed. CCTA can be successfully implemented for routine detection of CAV with good image quality and low radiation dose. CCTA allows CAV evaluation with the limited need for additional invasive testing.     

Metal artifact reduction for intracranial projectiles on post mortem computed tomography

PurposeTo compare the image quality of cranial post-mortem computed tomography (CT) obtained with and without projection-based single-energy metal artifact reduction (SEMAR) in cadavers with intracranial metallic ballistic projectiles.Materials and methodsFrom January 2017 to January 2018, cadavers with ballistic projectile head wounds with metal fragments and without massive head destruction were investigated using post-mortem CT. All subjects underwent CT using a conventional iterative reconstruction (IR) and SEMAR. To evaluate the impact of metallic artifacts, the total intracranial area (TA), non-interpretable zone (NIZ), disturbed interpretation zone (DZ), and artifact total surface (ATS) were delineated. Two independent readers identified extra-axial hemorrhage (EAH) and subarachnoid hemorrhage (SAH). Autopsy reports were used as the standard of reference.ResultsEleven corpses (10 males, 1 female; mean age, 62.8 ± 17.9 [SD] years) were evaluated. SEMAR showed a significant decrease in the ATS ratio with respect to conventional IR (72.1 ± 26.1 [SD] % [range: 26.8-99.1] vs. 86.4 ± 17.8 [SD] % [range: 37.2-100]; P < 0.001) and NIZ/TA ratios (11.6 ± 8.26% [range: 0.95–33.4] versus 42.5 ± 30.5% [range: 3.86–100]; P < 0.001). The interobserver reproducibility in diagnosing EAH and SAH was excellent with conventional IR (0.82) and good with SEMAR (0.75). SEMAR reduced uncertain diagnoses of EAH in 7 subjects for Reader 1 and in 6 for Reader 2, but did not influence the diagnosis of SAH for either reader.ConclusionSEMAR reduces the influence of metallic artifacts and increases the confidence with which the diagnosis of EAH can be made on post-mortem CT.     

A comparison between ultrasonography and mammography,computed tomography and digital subtraction angiography for the detection of breast cancers

Ultrasound (US) was compared with mammography (MMG), computed tomography (CT), and digital subtraction angiography (DSA) in its effectiveness to detect breast cancer masses and metastatic axillary nodes. Forty-seven breast cancer patients who all underwent MMG, US, CT, and DSA preoperatively in our institution between 1986 and 1990 were studied. US was able to detect tumors in all cases regardless of tumor size, whereas DSA detected T1-size tumors and MMG detected T2-size tumors in 40% and 64.7% of cases, respectively, being specifically inferior to US. It was found that MMG was least likely to detect papillotubular carcinoma, although microcalcification alone without a tumor mass on MMG improved detectability from 46.2% to 76.9%, according to the histological type. CT was found to be most sensitive to axillary node metastases (81.8%), followed by US (72.7%), but DSA was significantly unfavorable (42.9%). Thus, we concluded that US was superior to MMG, CT, and DSA for detecting breast cancer masses, but that CT was more advantageous than US, while DSA was of little value for evaluating axillary nodal status.     

Detection of significant coronary artery stenosis with cardiac dual-source computed tomography angiography in heart transplant recipients

Present study evaluates clinical feasibility of cardiac dual‐source computed tomography angiography (DSCTA) to detect significant coronary stenosis because of chronic allograft vasculopathy (CAV) after heart transplantation (HTX). An overall of 51 consecutive heart transplant recipients (43 men, 8 women, mean age: 52.3 ± 13.6 years) underwent DSCTA 1 ± 2 days before annual routine invasive coronary angiography (ICA). Three patients were excluded from further analysis. Total 714/717 (99.6%) segments in remaining 48 patients were depicted in diagnostic image quality by DSCTA with three vessel segments in two patients being additionally excluded because of motion artefacts. On a segment‐based analysis, sensitivity, specificity, and diagnostic accuracy (DA) for detection of significant stenosis were calculated as 100%, 98.9% and 98.9% respectively. On a patient‐based evaluation, sensitivity, specificity and DA were 100%, 86.0% and 93.0% respectively for remaining 46 patients. Negative predictive value (NPV) was 100%. DSCTA enables diagnosis and especially the exclusion of significant coronary artery stenosis in patients after HTX with a high NPV. The low rate of excluded vessel segments compared with former studies indicates improvement in image acquisition and robustness of latest scanner technology and thus may make subsequent annual invasive coronary angiography unnecessary.     

低剂量对比剂头颈部CT血管成像

目的探讨低剂量对比剂头颈部CTA成像的可行性。方法根据对比剂剂量和流率,将67例接受头颈部CTA的患者[对比剂均为碘帕醇(370mgI/ml)]随机分为2组:常规组(n=33)以固定流率(4ml/s)注入90ml对比剂和20ml生理盐水,个体化组(n=34)根据公式计算所需对比剂剂量和流率[对比剂剂量(ml)=体质量(kg)×λ(ml/kg);流率(ml/s)=对比剂剂量/(曝光时间+7);生理盐水剂量(ml)=(27.5-7-曝光时间)×流率。患者体质量为45～60kg时,λ=0.8ml/kg;61～75kg时λ=0.9ml/kg;>75kg时λ=1.0ml/kg]。测量主动脉弓、双侧颈总动脉分叉和双侧大脑中动脉起始段相应层面的增强CT值。采用单因素方差分析比较CT值和对比剂剂量,以t检验比较两组大脑中动脉图像质量。结果常规组和个体化组主动脉弓CT值分别为(414.20±6.24)HU、(435.36±6.44)HU(P<0.001);右颈总动脉分叉处CT值分别为(434.29±6.25)HU、(459.85±6.48)HU(P<0.001);左颈总动脉分叉处CT值分别为(435.42±6.26)HU、(458.43±6.42)HU(P<0.001)。常规组和个体化组右大脑中动脉起始段CT值分别为(291.03±10.08)HU、(267.55±9.88)HU(P=0.180);左大脑中动脉起始段CT值分别为(289.94±9.80)HU、(269.50±9.86)HU(P=0.169)。常规组每例对比剂剂量均为90ml,个体化组平均剂量为(59.41±7.91)ml(F=508.474,P<0.001)。常规组大脑中动脉图像质量等级优秀、良好和一般分别为28、4和1例,个体化组分别为27、6和1例(P=0.874)。结论通过个体化解决方案,降低头颈部CTA成像的对比剂剂量是切实可行的。     

64层CT诊断冠状动脉狭窄的准确性:与常规血管造影比较

目的评价64层螺旋CT冠状动脉造影对冠状动脉明显狭窄诊断准确性和可行性。方法218例冠心病疑似患者在一周内进行了64层CT冠状动脉造影及常规血管造影,对冠状动脉的主干及主要分支进行诊断,以冠状动脉造影结果为金标准评价64层CT诊断冠状动脉狭窄的准确性。结果多层螺旋CT所显示的2592支冠状动脉中冠状动脉狭窄173处,正确诊断166处,漏诊7处,误诊28处,敏感性95.9%,特异性98.6%,阳性预测值90.2%,阴性预测值99.7%,准确率98.4%。结论64层螺旋CT对冠状动脉狭窄诊断有较高的准确性,可作为高危人群普查筛选的首选方法之一。