多层CT胸痛三联检查的应用进展

随着多层CT(multi-slice CT,MSCT)技术的迅速发展,应用MSCT评价冠状动脉病变、肺动脉栓塞、主动脉夹层和其他胸部疾病已成为影像学研究的热点,本文对MSCT胸痛三联检查的应用进展进行综述。     

64 slice cardiovascular CT in the Emergency Department: concepts and first experiences

PURPOSE: The purpose of this study was to evaluate contrast-enhanced electrocardiogram (ECG)-gated 64-slice computed tomography (CT) angiography of the thorax as a triage tool in patients with acute equivocal chest pain. MATERIAL AND METHODS: Technical principles and diagnostic algorithms for using a single ECG-gated 64-slice CT scan for triple rule-out of acute pulmonary embolism, aortic dissection, acute coronary syndromes and other diseases of the chest are introduced. Our experience using this test in 23 patients are reviewed and exemplary cases are illustrated. The total length of hospitalisation and charges for Emergency Department care at the time of discharge were compared with a matched control population that underwent catheter angiography for emergent cardiac workup. Statistical analyses were performed with an independent Student's t test. Mann-Whitney rank sum test was also used on variables that did not have equal variance. RESULTS: Of the 23 patients, 11 presented without pathological findings, two with extensive pulmonary embolism, two with definite coronary artery disease (CAD) but stenosis <50% and eight with significant CAD (>50% stenosis). Catheter angiography was performed in the latter group, confirming the CT findings in all cases. Nine patients without CT findings were discharged on the same day. In comparison with the control group, length of hospitalisation (p=0.009) and total hospital charges (p<0.001) were significantly reduced. CONCLUSIONS: Our initial experience shows that ECG-gated 64- slice CT angiography of the entire thorax is technically feasible and enables rapid triage of patients to determine underlying cardiac and noncardiac reasons for chest pain. This test may thus help to significantly reduce costs and length of hospitalisation. Prospective studies involving larger groups of patients are required to confirm these findings.     

64排CT在急性胸痛诊断中的应用价值

目的:探讨64排CT对急性胸痛的诊断价值。方法:63例急性胸痛患者行64排CT回顾性心电门控胸部联合检查。采用MPR、MIP、CPR及VR等显示肺动脉、主动脉、冠状动脉及胸部、胸壁其他组织结构。由2名有经验的放射科医师对所有图像进行分析评价。结果:冠状动脉显影图像质量优占82.0%(672/820),良占12.9%(106/820),差占5.1%(42/820)。全部患者肺动脉和主动脉增强扫描后CT值≥200HU,均能达到诊断要求。心血管源性胸痛50例,其中冠状动脉病变29例,主动脉夹层11例,肺动脉栓塞8例,心包炎2例。非心血管源性胸痛7例,其中气胸3例,胸膜炎2例,肺部感染1例,食管疾病1例。6例未见异常。结论:64排CT胸部血管联合检查能清楚显示肺动脉、主动脉、冠状动脉,图像质量可以满足临床诊断要求,同时还能显示胸部其他疾病,在急性胸痛病因诊断中具有很高的临床应用价值。     

Increased prevalence of coronary artery calcification in patients with suspected pulmonary embolism

RATIONALE AND OBJECTIVES: The authors explored the possibility that patients with suspected pulmonary embolism are at high risk for coronary artery disease. To this purpose, they compared the presence of coronary artery calcification on computed tomography (CT) in patients suspected of pulmonary embolism with age- and gender-matched controls. MATERIALS AND METHODS: The CT scans of 214 patients were reviewed. Of those, 107 consecutive patients (50%) had pulmonary CT angiography for suspected pulmonary embolism (PE group). The remaining 107 age- and gender-matched patients were scanned for reasons other than pulmonary embolism (non-PE group). All CT scans were performed with the same 8-detector-row multislice scanner. Two radiologists reviewed scans of 5-mm slices using a five-grade modified coronary calcium scoring system: 1 = no calcification; 2 = minimal calcification; 3 = mild calcification; 4 = moderate calcification; and 5 = severe calcification. The Marginal Homogeneity test was used to compare the distribution and severity of calcification in the two groups. RESULTS: Of 107 patients in the PE group, seven (6.54%) had pulmonary embolism detected on CT. Coronary artery calcification was detected in 61 patients (57%) in the PE group compared with 42 patients (39%) in the non-PE group. The Marginal Homogeneity test showed that patients with pulmonary embolism symptoms were 2.9 times more likely to have calcification detected compared with those patients who had chest CT for some other reason (P = .0034). However, in patients in whom coronary artery calcification was detected, the distribution of severity of calcification was the same in both groups. CONCLUSION: Assuming coronary artery calcification indicated coronary atherosclerosis, patients undergoing CT for suspected pulmonary embolism may be at high risk for coronary artery disease.     

16排螺旋CT在高危胸痛诊断中的应用

目的:通过一次CT扫描同时完成冠状动脉、主动脉和肺动脉CTA检查,鉴别上述高危胸痛,探讨16排螺旋CT在高危胸痛诊断中应用价值。方法:2005年12月~2008年6月住院及急诊胸痛患者46人。应用两种方法行行一次性胸痛三联检查。结果:46例患者一次检查均可清晰显示肺动脉段以上分支、胸主动脉及冠状动脉左右主干及主要分支。共发现冠状动脉狭窄42例,肺动脉栓塞5例,主动脉夹层2例。结论:16排螺旋CT一次动脉期增强扫描显示肺动脉、胸主动脉及冠状动脉,对胸痛病因的诊断及鉴别诊断具有重要意义。     

64层螺旋CT心胸联合造影在急性胸痛病因鉴别诊断中的价值

目的 探讨64层螺旋CT在急性胸痛病因鉴别诊断中的临床价值。方法 对36例临床急性胸痛的患者行64层螺旋CT心胸联合血管造影检查。对所有扫描原始数据用冠状、矢状面多平面重组（MPR）、曲面重组（CPR）、容积再现（VR）和最大密度投影（MIP）等方法行冠状动脉、肺动脉和胸主动脉成像。由2名有经验的放射科医生对所有图像进行观察，对疾病进行诊断，其中16例患者同时行选择性血管造影检查。结果 所有行64层螺旋CT心胸联合血管造影的患者1次检查均可清晰显示双侧肺动脉、冠状动脉主干及其主要分支以及胸主动脉，同时均可进行纵隔及肺窗重组，对胸部疾病进行诊断。显示冠状动脉狭窄10例，急性肺动脉栓塞14例，主动脉夹层6例（其中1例同时伴有冠状动脉右支急性血栓形成）；并诊断气胸1例、缩窄性心包炎1例；4例未见明显异常。结论 64层螺旋CT1次心胸联合血管造影检查能清晰地显示冠状动脉、肺动脉及主动脉，对其病变作出正确诊断，还能清晰地显示胸部疾病，是急性胸痛病因诊断无创、可靠的检查方法。     

Behcet综合征累及心血管系统的CT诊断

目的 探讨累及心血管系统的Behcet综合征影像特点及其诊断.方法 搜集1995年7月至2007年12月临床诊断为Behcet综合征累及心血管系统患者11例的电子束CT(EBCT)或64层MSCT检查资料,回顾分析其cT影像特点.结果 11例Behcet综合征患者的CT影像表现为:累及主动脉瓣4例(其中2例同时累及二尖瓣),右冠状动脉假性动脉瘤2例(其中1例同时形成右腋动脉假性动脉瘤,3.5年后无诱因出现腹主动脉假性动脉瘤),左锁骨下动脉假性动脉瘤1例(伴腹主动脉下段闭塞),主动脉弓部真性动脉瘤及溃疡1例,主动脉弓部假性动脉瘤1例,主动脉夹层1例,肺动脉栓塞伴房间隔瘤1例.结论 CT作为Behcet综合征诊断及定期随访的检查手段,可明确心血管系统受累情况,根据其病变的影像特点,为选择临床治疗方法提供依据.     

Dual-source CT for chest pain assessment

Comprehensive CT angiography protocols offering a simultaneous evaluation of pulmonary embolism, coronary stenoses and aortic disease are gaining attractiveness with recent CT technology. The aim of this study was to assess the diagnostic accuracy of a specific dual-source CT protocol for chest pain assessment. One hundred nine patients suffering from acute chest pain were examined on a dual-source CT scanner with ECG gating at a temporal resolution of 83 ms using a body-weight-adapted contrast material injection regimen. The images were evaluated for the cause of chest pain, and the coronary findings were correlated to invasive coronary angiography in 29 patients (27%). The files of patients with negative CT examinations were reviewed for further diagnoses. Technical limitations were insufficient contrast opacification in six and artifacts from respiration in three patients. The most frequent diagnoses were coronary stenoses, valvular and myocardial disease, pulmonary embolism, aortic aneurysm and dissection. Overall sensitivity for the identification of the cause of chest pain was 98%. Correlation to invasive coronary angiography showed 100% sensitivity and negative predictive value for coronary stenoses. Dual-source CT offers a comprehensive, robust and fast chest pain assessment.     

Thorax: new millennium vascular imaging

In recent years the technological development of computed tomography (CT) and magnetic resonance (MR) has promoted new improvements in diagnosis by means of imaging. In particular the introduction of multislice CT and MR angiography (MRA) has broadened the non-invasive diagnostic possibilities in the vascular study of the thorax. The new technological developments of CT and MR enable functional studies as well. Recent studies have demonstrated that CT and MR are as accurate in finding the vascular anomalies as digital subtraction angiography, while they are more precise in recognising possible associated pathologies which modify therapeutic treatment (for example of the trachea, bronchi, oesophagus etc.). There are many vascular structures in the thorax which need to be considered (aorta, pulmonary and coronary arteries, pulmonary veins, vena cava). The field of associated pathologies is also broad, and includes congenital vascular anomalies, vascular malformations, aorta dissection, vascular compression syndromes, atherosclerotic stenosis or occlusions, and pulmonary embolism. In pulmonary embolism some authors have demonstrated the utility of CT, in showing pulmonary segmental perfusion defects, and MRA, in identifying sub-segment pulmonary embolism. In this paper we analyse the most important CT and MR applications for the study of vascular thoracic diseases and compare them with other diagnostic techniques. We also evaluate the morpho-functional capabilities of CT and MR in this field.     

Cardiac CT for the assessment of chest pain: Imaging techniques and clinical results

Immediate and efficient risk stratification and management of patients with acute chest pain in the emergency department is challenging. Traditional management of these patients includes serial ECG, laboratory tests and further on radionuclide perfusion imaging or ECG treadmill testing. Due to the advances of multi-detector CT technology, dedicated coronary CT angiography provides the potential to rapidly and reliably diagnose or exclude acute coronary artery disease. Life-threatening causes of chest pain, such as aortic dissection and pulmonary embolism can simultaneously be assessed with a single scan, sometimes referred to as "triple rule out" scan. With appropriate patient selection, cardiac CT can accurately diagnose heart disease or other sources of chest pain, markedly decrease health care costs, and reliably predict clinical outcomes. This article reviews imaging techniques and clinical results for CT been used to evaluate patients with chest pain entering the emergency department.     

320层CT心电门控双期心脏功能扫描一站式检查的初步研究

目的 初步探讨应用320层CT心电门控双期心功能扫描模式(DPCFA)一站式评价心脏、冠状动脉、肺动脉形态及左、右心室功能的能力.方法 回顾性分析40例经临床确诊患者的320层CT DPCFA扫描数据,分别以肺动脉期重建并观察肺动脉分支,以主动脉期重建并观察冠状动脉.分别以两期数据进行MPR重组并分析左、右心室功能,结果与超声心动图相对照.5例因图像质量欠佳排除组外,35例图像质量达到2级以上,可用作诊断,扫描平均心率(71.2±11.2)次/min,全部患者扫描期间未出现心律失常.应用Pearson检验进行相关性分析,应用配对t检验分析二者测量左心室射血分数(LVEF)的一致性.结果 (1)35例最终入组患者中,诊断单发肺动脉栓塞l1例,冠心病支架术后7例,单发冠心病5例,先天性心脏病房间隔缺损3例,特发性肺动脉高压3例,左房黏液瘤l例,肺动脉栓塞合并冠心病5例,全部符合临床诊断.(2)CT与超声心动图对照,35例患者的左、右心室舒张末期最大径分别为(36.7±3.3)、(43.3±3.4)mm,左、右心室收缩末期最大径分别为(31.6 ±5.1)、(41.3±5.1)mm,LVEF为47.1±15.1.超声心动图测得左、右心室舒张末期最大径分别为(40.3±3.1)、(47.3±4.2)mm,左、右心室收缩末期最大径分别为(37.3±5.6)、(45.3±3.3)mm,LVEF为46.0±14.8.CT与超声测量结果有显著的相关性(r=0.886～0.988,P值均＜0.01),LVEF的测量结果差异无统计学意义(t=0.692,P＞0.05).(3)应用DPCFA技术,平均射线剂量(5.4 ±0.5)mSv.结论 320层CT心电门控双期心功能扫描模式,可以用于心血管疾病一站式影像检查,可为临床心血管疾病的诊断、鉴别诊断、治疗方案的确定提供丰富的影像学信息,对左、右心功能不全相关临床问题的处理具有指导作用.

Abstract：

Objective To explore the feasibility of evaluating cardiac structure, coronary artery,pulmonary artery and cardiac function in one single scan by 320-row CT ECG-gated double phase cardiac function scan mode. MethodsForty patients underwent the 320-detector row CT double phase cardiovascular angiography. The pulmonary phase and aortic phase were reconstructed in order to evaluate the pulmonary and coronary artery. MPR reconstructions of both pulmonary and aortic phase were used to analyze the function of the two ventricles. And the results of the cardiac function were compared with those of transthoracic echocardiography. Thirty-five cases could be analyzed and diagnosed, while the other 5 cases had to be given up because of the poor imaging quality. The mean heart rate was (71.2 ± 11.2) beat per min (bpm). No arrhythmia case included. Results ( 1 ) Pulmonary embolism were diagnosed in 11 cases,coronary artery disease (CAD) were found in 5 cases, while post-stent implantation were observed in 7 cases. Six cases of congenital heart disease were diagnosed with 3 ASD and 3 primary pulmonary hypertension. Another one was diagnosed with left atrial myxoma, and 5 cases were pulmonary embolism associated with CAD. All of above cases were verified by final clinical diagnosis. (2) The heart function parameters including LVEDd , RVEDd, LVESd, RVESd and LVEF were (36.7 ±3.3), (43.3 ± 3.4) mm,(31.6±5.1), (41.3 ±5.1) mm and (47.1 ±15.1) for CT, while those were (40.3 ±3.1), (47.3 ±4.2) mm,(37.3 ±5.6), (45.3 ±3.3) mm,and (46.0 ± 14.8) for ultrasound, respectively. The CT results were correlated with the ultrasound ( n = 35, r = 0.886-0.988, P ＜ 0.01 ). (3) The average radiation exposure was ( 5.4 ± 0.5 ) mSv. Conclusions 320-row CT ECG-gated double phase cardiac function scan mode is feasible for the "one-stop-shop" examination of the cardiovascular disease. This noninvasive method is recommended for the diagnosis, differential diagnosis, treatment and prognosis of cardiovascular disease.     

Electrocardiographically gated 16-section CT of the thorax: cardiac motion suppression

Thirty patients underwent 16-section multi-detector row computed tomographic (CT) angiography of the thorax with retrospective electrocardiographic gating. Institutional review board approval was obtained for retrospective analysis of CT scan data and records; patient informed consent was not required. Images reconstructed at six different time points (0%, 20%, 40%, 50%, 60%, 80%) within the R-R interval on the electrocardiogram were analyzed by two radiologists for diagnostic quality, to identify suitable reconstruction intervals for optimal suppression of cardiac motion. Five regions of interest (left coronary artery, aortic root, ascending and descending aorta, pulmonary arteries) were evaluated. Best image quality was achieved by referencing image reconstruction to middiastole (50%-60%) for the left coronary artery, aortic root, and ascending aorta. The pulmonary arteries are best displayed during mid- to late diastole (80%).     

Patent foramen ovale,paradoxical embolism and fatal coronary obstruction

A 75-year-old woman was admitted to the emergency room with chest pain and vomiting. An electrocardiogram and laboratory results were suggestive for myocardial infarction of the posterior cardiac wall. Echocardiography was indicative of aortic dissection, and a CT scan of the thoracic arteries showed a massive pulmonary thromboembolism and thrombotic occlusion of the right coronary artery (RCA). The woman died shortly after admission. Autopsy confirmed the presence of thromboemboli in the right pulmonary artery and its lobar branches. Also, the anterior aortic sinus was filled with a 9 cm long thromboembolus that extended into the RCA, making it dilated and completely occluded. Another 3.5 cm long thromboembolus extended from the beginning of the left subclavian artery. A patent foramen ovale (PFO) was present. On the posterior wall of the left ventricle, there was an area suggestive of myocardial infarction, and histopathological examination confirmed that it was 24–48 hours old. The coronary circulation was “co-dominant”. The sources of thrombotic masses were the deep veins of the lower limbs. The cause of death was myocardial infarction, caused by RCA occlusion with thromboembolus originating from the deep veins of the left lower leg after paradoxical embolism via PFO. This case illustrates that although deep venous thrombosis, pulmonary thromboembolism, and PFO are not rare findings at autopsy, their combination could be a relatively rare cause of fatal coronary artery occlusion after paradoxical embolism.     

Comprehensive cardiovascular ECG-gated MDCT as a standard diagnostic tool in patients with acute chest pain

Acute myocardial infarction, pulmonary embolism, and aortic dissection are diseases associated with acute chest pain and may lead to severe morbidity and mortality. These diseases may not be trivial to diagnose in the settings of emergency room. ECG-gated multi-detector computed tomography (MDCT), already established for the assessment of pulmonary embolism and aortic dissection, provides reliable information regarding the triage of patients with acute coronary syndrome in the emergency room. MDCT recently appeared to be logistically feasible and a promising comprehensive method for the evaluation of cardiac and non-cardiac chest pain in emergency department patients. The possibility to scan the entire thorax visualizing the thoracic aorta, the pulmonary arteries, and the coronary arteries could provide a new approach to the triage of acute chest pain. The inherent advantage of MDCT with cardiac state-of-the-art capabilities is the rapid investigation of the main sources of acute chest pain with a high negative predictive value. Recent studies also reports an advantage in terms of costs. With current evidence, the selection of patients with acute chest pain candidates to MDCT should remain restricted to avoid unjustified risk of ionizing radiation.     

64排螺旋CT肺动脉与主动脉联合扫描技术

目的：探讨一次性完成肺动脉与主动脉 CT 造影检查技术。方法回顾性分析23例肺动脉与主动脉联合造影的患者CT 影像资料(A 组),另选肺动脉、主动脉 CT 造影正常的患者各13例为对照(B 组、C 组)。统计3组患者对比剂应用剂量和辐射剂量,观察异常血管显示情况,对比各组间正常肺动脉、主动脉 CT 值,以及4、5级肺动脉显示数量。结果A 组对比剂用量大于 B组和 C 组,但小于 B 组与 C 组之和;A 组辐射剂量与 C 组相当,明显少于 B 组与 C 组之和。23例中准确诊断6例肺动脉栓塞,1例肺动脉发育畸形;4例主动脉夹层,真假腔对比明显,5例主动脉炎,10例主动脉粥样硬化;结果正常者4、5级肺动脉显示数量、肺动脉与主动脉 CT 值和对照组对比均无统计学意义(P >0.05)。结论64排螺旋 CT 可一次性完成肺动脉与主动脉造影检查,对比剂用量和辐射剂量明显减少。     

多层螺旋CT血管造影技术在胸部大血管急症中的应用

目的评价多层螺旋CT血管造影技术在胸部大血管急诊病例诊断中的临床应用价值。方法25例胸部大血管急症病例行多层螺旋CT血管造影检查,结合二维和三维重建技术进行图像分析。结果中央型肺栓塞10例,夹层动脉瘤12例,动脉瘤2例,多发大动脉炎合并肾动脉狭窄1例。二维图像(多平面容积重建及曲面重建)较好显示病变范围、大小及病变细节,而三维重建(最大密度投影、表面遮盖成像和容积重建)良好显示管壁钙化情况和病变空间关系。仿真内窥镜可以判断肺动脉内栓子与血管壁关系、显示夹层动脉瘤的内膜破口情况、内膜片与血管关系。结论多层螺旋CT血管造影结合影像后处理技术是一种有效的诊断胸部大血管急诊的检查方法。     

Triple rule-out CT in the emergency department: protocols and spectrum of imaging findings

Triage decisions in patients suffering from acute chest pain remain a challenge. The patient’s history, initial cardiac enzyme levels, or initial electrocardiograms (ECG) often do not allow selecting the patients in whom further tests are needed. Numerous vascular and non-vascular chest problems, such as pulmonary embolism (PE), aortic dissection, or acute coronary syndrome, as well as pulmonary, pleural, or osseous lesions, must be taken into account. Nowadays, contrast-enhanced multi-detector-row computed tomography (CT) has replaced previous invasive diagnostic procedures and currently represents the imaging modality of choice when the clinical suspicion of PE or acute aortic syndrome is raised. At the same time, CT is capable of detecting a multitude of non-vascular causes of acute chest pain, such as pneumonia, pericarditis, or fractures. Recent technical advances in CT technology have also shown great advantages for non-invasive imaging of the coronary arteries. In patients with acute chest pain, the optimization of triage decisions and cost-effectiveness using cardiac CT in the emergency department have been repetitively demonstrated. Triple rule-out CT denominates an ECG-gated protocol that allows for the depiction of the pulmonary arteries, thoracic aorta, and coronary arteries within a single examination. This can be accomplished through the use of a dedicated contrast media administration regimen resulting in a simultaneous attenuation of the three vessel territories. This review is intended to demonstrate CT parameters and contrast media administration protocols for performing a triple rule-out CT and discusses radiation dose issues pertinent to the protocol. Typical life-threatening and non-life-threatening diseases causing acute chest pain are illustrated.     

Computed tomographic coronary angiography in patients with surgically treated type A aortic dissection: preliminary results

Acute type A aortic dissection is a serious emergency with a mortality rate of up to 40% within the first 24 h when left untreated. Surgical therapy needs to be initiated promptly. Due to this urgent situation, preoperative evaluation of the coronary arteries is not routinely performed in these patients. The aim of this study was to evaluate the accuracy of 64-slice computed tomography angiography (CTA) for postoperative coronary artery assessment in these patients. Ten consecutive patients with two or more cardiovascular risk factors were prospectively enrolled. Patients had type A aortic dissection treated surgically with a supracoronary graft of the ascending aorta. Performance of CTA to exclude significant stenosis (>50% lumen narrowing) and/or coronary artery dissection was compared with quantitative coronary angiography. A total of 147 segments were evaluated. Three segments (2%) were excluded from analysis. CTA correctly assessed one of three significant stenoses in three patients and correctly excluded coronary artery disease (CAD) in six of ten patients. One patient was rated false positive. Overall accuracy, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of CT for identifying coronary artery disease by segment was 98%, 33%, 99%, 50%, and 99%, respectively (P < 0.05). By patient, it was 70%, 33%, 86%, 50%, and 75%, respectively. No coronary artery dissection was found. Noninvasive CTA may be a viable alternative to conventional angiography for postoperative coronary artery evaluation in patients with surgically treated type A aortic dissection and cardiovascular risk factors. An NPV of 99% should allow for reliable exclusion of CAD. Further studies with higher patient numbers are warranted.     

Detection of central pulmonary embolism on computed tomography densitometry images before computed tomography pulmonary angiography

OBJECTIVE: The purpose of this article is to describe the imaging findings of acute central pulmonary embolism on computed tomography (CT) densitometry images performed before contrast-enhanced CT pulmonary angiography. METHODS: A retrospective review was conducted of reports from all CT pulmonary angiograms performed at our institution, and cases of acute central pulmonary embolism, defined as those with clot in the main, left, or right pulmonary arteries, were identified. Images of positive studies were reviewed on a picture archiving and communications system (PACS) workstation. RESULTS: A total of 1282 CT pulmonary angiograms were obtained for evaluation of possible acute pulmonary embolism, and 1 combined CT aortogram and pulmonary angiogram was performed for aortic dissection and acute pulmonary embolism. Two hundred fourteen (16.7%) examinations positive for acute pulmonary embolism were identified, 26 (12.1%, 2.0% of total examinations) of which had central clots. Of the 26 patients with central acute pulmonary embolism, 12 (46.1%, 5.6% of all positive studies and 0.9% of all CT pulmonary angiograms) had clots that were visible on the densitometry images. CONCLUSION: Although an uncommon finding, acute central pulmonary embolism can be detected on CT densitometry performed to optimize opacification of the pulmonary arteries for CT pulmonary angiography and may prove useful in selected clinical situations.     

Cardiac computed tomographic angiography: evaluation of non-cardiac structures

Cardiac computed tomography is a promising new technology for non-invasive evaluation of the coronary arteries. As CT is inherently a high resolution volumetric imaging modality, data from structures other than the heart can be accessed in studies performed primarily for cardiac indications. Current generation scanners can easily detect abnormalities such as pulmonary emboli and aortic dissection on routine coronary CT angiograms. Many other abnormalities such as small pulmonary nodules can also be detected. While major abnormalities like aortic dissection are of obvious clinical importance, detection of incidental abnormalities such as small pulmonary nodules less than 4 mm in diameter has not yet been shown to positively affect patient outcomes, and may lead to unnecessary testing. Recommendations for image reconstruction and training in interpretation of incidental findings continue to evolve, but most agree that coronary CT angiography should be focused primarily on the coronary arteries.