Prevalence of significant extracoronary findings on multislice CT coronary angiography examinations and coronary artery calcium scoring examinations

Collateral findings during computed tomography scan for atrial fibrillation ablation: Let’s take a look around

The growing number of atrial fibrillation catheter ablation procedures warranted the development of advanced cardiac mapping techniques, such as image integration between electroanatomical map and cardiac computed tomography. While scanning the chest before catheter ablation, it is frequent to detect cardiac and extracardiac collateral findings. Most collateral findings are promptly recognized as benign and do not require further attention. However, sometimes clinically relevant collateral findings are detected, which often warrant extra diagnostic examinations or even invasive procedure, and sometimes need to be followed-up over time. Even though reporting and further investigating collateral findings has not shown a clear survival benefit, almost all the working groups providing data on collateral findings reported some collateral findings eventually coming out to be malignancies, sometimes at an early stage. Therefore, there is currently no clear agreement about the right strategy to be followed.

Detection of Cardiac Incidental Findings on Routine Chest CT: The Impact of Dedicated Training in Cardiac Imaging

PURPOSE

Routine chest CT and cardiac CT angiography (CTA) both image the heart, albeit with different precision and intent. The aim of this study was to evaluate the diagnostic ability of radiologists with different levels of cardiac training to identify cardiac findings on chest CT without electrocardiographic gating compared with a reference standard of electrocardiographically gated cardiac CTA.

METHODS

Electrocardiographically gated cardiac CT angiographic studies performed between January 2005 to January 2010 in patients with routine chest CT within six months were retrospectively identified. Fourteen radiologists at four stages of training (stage 1, residents with no cardiac training [n = 4]; stage 2, residents who had completed at least one dedicated rotation of cardiac imaging [n = 3]; stage 3, radiologists without cardiac training [n = 3]; and stage 4, radiologists with formal cardiac fellowship training [n = 4]) performed blinded, anonymized cardiac readings of chest CT images. Findings were categorized (coronary arterial, noncoronary vessel, cardiac chamber, myocardial, pericardial, and valve findings) with cardiac CTA as a reference standard.

RESULTS

Overall, 140 cardiac CT angiographic findings were reported in 63 of 77 patients. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of nongated CTA were 43.6%, 96.8%, 83.0%, 81.6%, and 81.8%, respectively, for all readers. Increasing training was associated with higher sensitivity (30.3%, 35.7%, 45.7%, and 61.2% from stages 1 to 4) but similar specificity (96.4%, 96.7%, 96.3%, and 97.6% from stages 1 to 4). Frequently missed findings categories were coronary arterial, myocardial, and cardiac chamber findings.

CONCLUSIONS

Increasing cardiac imaging training correlates with increased sensitivity and stable specificity to detect cardiac findings on routine chest CT without electrocardiographic gating. Cardiac findings should be noted on chest CT when observed, and cardiac training should be encouraged.

The prevalence and significance of thoracic findings in patients undergoing extended coverage computed tomography for assessment of abdominal aortic aneurysms

OBJECTIVE

Many major vascular centres, including ours, incorporate coverage of the thoracic aorta in CT scans evaluating abdominal aortic aneurysms (AAAs) (extended coverage contrast-enhanced CT (EC-CECT) scan]. We sought to determine the prevalence of thoracic pathology in a large consecutive series of patients with AAA undergoing EC-CECT.

METHODS

All patients who underwent EC-CECT for AAA between April 2013 and 2014 were identified from our radiology information system. Reports were retrospectively reviewed and for each study, sex, age and reported thoracic aortic and other non-vascular findings were extracted. Findings were initially categorized into "major" or "minor" depending on if they were mentioned in the report impression/conclusion. Any major thoracic pathology was termed "significant" if there was a new diagnosis/patient intervention/investigation and a change in patient management.

RESULTS

Of the 150 scans included in the study, 97 (65%) had at least one thoracic finding. These findings included 24 scans (16%) with major findings and 73 scans (48%) with minor findings. In 13 scans (9%), the findings were significant and resulted in a delay (n = 11) or cancellation (n = 2) of AAA repair.

CONCLUSION

Pre-procedural EC-CECT helps to identify significant intrathoracic findings in patients with AAA, which can have a major impact on AAA repair. This study supports the routine use of pre-procedural EC-CECT in planning AAA repair.

ADVANCES IN KNOWLEDGE

This study describes the prevalence of significant thoracic pathology, which can impact on AAA repair. This information could potentially change the pre-procedure imaging protocol for patients with AAA.

Relevant incidental findings at abdominal multi-detector contrast-enhanced computed tomography: A collateral screening?

AIM: To investigate the prevalence of relevant incidental findings (RIFs) detected during routine abdominal contrast-enhanced computed tomography (CeCT).

METHODS: We retrospectively evaluated the reports of a consecutive series of abdominal CeCT studies performed between January and May 2013. For each report, patients’ age and sex, admission as inpatient or outpatient, clinical suspicion as indicated by the requesting physician, availability of a previous abdominal examination, and name of the reporting radiologist were recorded. Based on the clinical suspicion, the presence and features of any RIFs (if needing additional workup) was noted.

RESULTS: One thousand forty abdominal CeCT were performed in 949 patients (528 males, mean age 66 ± 14 years). No significant difference was found between inpatients and outpatients age and sex distribution (P > 0.472). RIFs were found in 195/1040 (18.8%) CeCT [inpatients = 108/470 (23.0%); outpatients = 87/570 (15.2%); P = 0.002]. RIFs were found in 30/440 (6.8%) CeCT with a previous exam and in 165/600 (27.5%) without a previous exam (P < 0.001). Radiologists’ distribution between inpatients or outpatients was significantly different (P < 0.001). RIFs prevalence increased with aging, except for a peak in 40-49 year group. Most involved organs were kidneys, gallbladder, and lungs.

CONCLUSION: A RIF is detected in 1/5 patients undergoing abdominal CeCT. Risk of overdiagnosis should be taken into account.

Collateral non cardiac findings in clinical routine CT coronary angiography: results from a multi-center registry

PURPOSE

The aim of the study was to evaluate the prevalence of collateral findings detected in computed tomography coronary angiography (CTCA) in a multi-center registry.

MATERIALS AND METHODS

We performed a retrospective review of 4303 patients (2719 males, mean age 60.3 ± 10.2 years) undergoing 64-slice CTCA for suspected or known coronary artery disease (CAD) at various academic institutions between 01/2006 and 09/2010. Collateral findings were recorded and scored as: non-significant (no signs of relevant pathology, not necessary to be reported), significant (clear signs of pathology, mandatory to be reported), or major (remarkable pathology, mandatory to be reported and further investigated).

RESULTS

We detected 6886 non-cardiac findings (1.6 non cardiac finding per patient). Considering all centers, only 865/4303 (20.1 %) patients were completely without any additional finding. Overall, 2095 (30.4 %) non-significant, 4486 (65.2 %) significant, and 305 (4.4 %) major findings were detected. Among major findings, primary lung cancer was reported in 21 cases. In every center, most prevalent significant findings were mediastinal lymph nodes >1 cm. In 256 patients, collateral findings were clinically more relevant than coexisting CAD and justified the symptoms of patients.

CONCLUSIONS

The prevalence of significant and major collateral findings in CTCA is high. Radiologists should carefully evaluate the entire scan volume in each patient.

Looking outside the "cardiac" box: incidental detection of a metastatic lung tumor on cardiac position emission tomography/computed tomography

Incidental extracardiac findings are not uncommon in patients undergoing cardiac positron emission tomography/computed tomography (PET/CT) and some of these findings can have significant clinical impact. We report a case of a 74-year-old man who presented with dyspnea and left sided chest pain. 82-rubidium PET/CT imaging showed normal myocardial perfusion. Review of the low dose CT scan performed for attenuation correction purposes (CTAC) incidentally revealed a 4 cm mass in the left lung, which was histologically shown to be a squamous cell carcinoma. A subsequent staging CT showed chest wall metastases and rib destruction in the upper left thorax, which were outside the image reconstruction field of view of the CTAC. This report illustrates the importance of vigilant review of all acquired images by the PET/CT reader to look for extracardiac abnormalities that may explain symptoms in the absence of coronary artery disease. It also raises the question as to whether a larger field of CT image acquisition should be routinely performed to scan the entire chest during cardiac PET/CT imaging. However, the latter needs to be weighed against the increase in patient dose, which we estimated to be an additional 15%.

The prevalence and clinical importance of incidentally detected noncoronary cardiovascular findings with coronary multidetector CT angiography

OBJECTIVE

The purpose of this study was to determine the prevalence and clinical importance of incidental findings of noncoronary cardiac structures and mediastinal great vessels in patients who underwent coronary computed tomography angiography (CCTA).

METHODS

The study included 2,096 consecutive patients (1,472 men and 624 women, with a mean age of 55 years). Cardiovascular findings were categorized into three groups according to the clinical importance: group 1 included findings necessitating immediate treatment or intervention; group 2 included findings requiring clinical awareness, follow-up, or further clinical and/or radiological investigations; and group 3 included findings not requiring any follow-up or further tests. We also evaluated whether there was any previous diagnosis of cardiovascular findings.

RESULTS

A total of 174 abnormalities (8.3 %) were detected in 170 patients. Of these abnormalities, 21 findings (12 %) were considered as group 1, 121 (69.5 %) as group 2, and 32 (18.5 %) as group 3. The majority of cardiovascular findings (140 of 174, 80.5 %) were unknown by the reporter during the interpretation of CCTA examinations and regarded as incidental findings.

CONCLUSION

Noncoronary incidental cardiovascular findings in patients who underwent CCTA are common. It is important to be aware of these findings necessitating immediate treatment or intervention, and follow-up or further investigations, and careful attention must be paid to all the structures included in the images.

Incidental findings on cardiac computed tomography in incident hemodialysis patients: the predictors of arrhythmic and cardiovascular events in end-stage renal disease (PACE) study

BACKGROUND

This is the first study that has examined non-cardiac incidental findings in research cardiac computed tomography (CT) of hemodialysis patients and their relationship with patient characteristics.

METHODS

We performed a cross-sectional analysis in the Predictors of Arrhythmic and Cardiovascular Events in End-Stage Renal Disease (PACE) study, a prospective cohort study on incident hemodialysis patients. Non-cardiac structures in the cardiac CT scan were reviewed and evaluated. The type and frequencies of non-cardiac incidental CT findings were summarized. Univariate and multivariate logistic regression were performed to analyze the associations between gender, older age, obesity, history of cardiovascular disease (CVD), smoking status, history of chronic pulmonary disease and history of cancer with presence of any incidental CT findings and, separately, pulmonary nodules.

RESULTS

Among the 260 participants, a total of 229 non-cardiac incidental findings were observed in 145 participants (55.8% of all participants). Of these findings, pulmonary nodules were the most common incidental finding (24.2% of all findings), and 41.3% of them requiring further follow-up imaging per radiology recommendation. Vascular and gastrointestinal findings occurred in 11.8% and 15.3% of participants, respectively. Participants 65 years or older had a higher odds of any incidental findings (Odds Ratio (OR) =2.55; 95% Confidence Intervals (CI) 1.30, 4.99) and pulmonary nodules (OR=4.80; 95% CI 2.51, 9.18). Prior history of CVD was independently and significantly associated with any incidental findings (OR=2.00; 95% CI 1.19, 3.40); but not with the presence of pulmonary nodules.

CONCLUSIONS

We demonstrate that the prevalence of incidental findings by cardiac CT scanning is extremely high among patients on hemodialysis. Further investigations to follow-up on the high occurrence of incidental findings during our research study and potentially clinical studies raises important practical, ethical and medico-legal issues that need to be carefully considered in research projects using imaging studies.

Coronary calcium scoring: are the results comparable to computed tomography coronary angiography for screening coronary artery disease in a South Asian population?

Background

The need of having feasible screening tools like Coronary Calcium Scoring (CCS) and CT Coronary Artery (CTCA) for Coronary Artery Disease (CAD) has become paramount. We aimed to evaluate the accuracy of CCS in determining the degree of stenosis of coronary vessels as compared to that determined by CTCA in a South Asian population.

Methods

A retrospective study was conducted at The Aga Khan University Hospital. A total of 539 patient records were reviewed who had undergone CCS and CTCA between 2008 and 2010. Patient records were reviewed by comparing their CCS and CTCA results.

Results

About 268 out of 301 (89%) patients with a CCS of 0–9 were found to be free of stenosis on CTCA. On a CCS of 10–99, 110 out of 121 (91%) patients were either free of stenosis or had mild stenosis. About 66 out of 79 (84%) patients had moderate or severe stenosis with a calcium score of 100–400 while none of the patients were free of stenosis. Around 28 out of 38 (74%) patients with a CCS of more than 400 had severe stenosis. However, only 04 patients (11%) were found to have mild stenosis. Spearman’s rho revealed a correlation coefficient of 0.791 with a p-value of <0.001.

Conclusion

Our study reaffirms that in South Asian population, low CCS (<100) is associated with no or minimal stenosis while high CCS warrants further investigation; hence, making it a reliable tool for screening patients with CAD.

A fateful kiss: the use of CT coronary angiogram in the diagnosis of non-cardiac chest pathology

A 34-year-old dental nurse presented with a 2-day history of retrosternal chest pain that was constant and 'burning' in nature. She was otherwise fit and well, no significant prior medical history and no ischaemic heart disease risk factors. Clinical examination was entirely normal apart from pyrexia of 38.3°C. Admission ECG showed ST depression in the inferior and anterolateral leads suggestive of myocardial ischaemia, consequently a CT coronary angiogram (CTCA) was performed. This showed normal coronary arteries, incidental distal oesophageal thickening was seen. Further history taking revealed that her youngest daughter had recently suffered from cold sores. The patient went on to have a diagnostic procedure, an oesophagogastroduodenoscopy. Biopsies confirmed acute oesophagitis with features suggestive of herpes virus infection. The patient responded promptly to oral acyclovir. This case highlights the value of CT coronary angiogram in identifying non-cardiac pathology in patients with a low pretest probability of coronary artery disease.

Unrequested findings on cardiac computed tomography: looking beyond the heart

Objectives

To determine the prevalence of clinically relevant unrequested extra-cardiac imaging findings on cardiac Computed Tomography (CT) and explanatory factors thereof.

Methods

A systematic review of studies drawn from online electronic databases followed by meta-analysis with meta-regression was performed. The prevalence of clinically relevant unrequested findings and potentially explanatory variables were extracted (proportion of smokers, mean age of patients, use of full FOV, proportion of men, years since publication).

Results

Nineteen radiological studies comprising 12922 patients met the inclusion criteria. The pooled prevalence of clinically relevant unrequested findings was 13% (95% confidence interval 9–18, range: 3–39%). The large differences in prevalence observed were not explained by the predefined (potentially explanatory) variables.

Conclusions

Clinically relevant extra-cardiac findings are common in patients undergoing routine cardiac CT, and their prevalence differs substantially between studies. These differences may be due to unreported factors such as different definitions of clinical relevance and differences between populations. We present suggestions for basic reporting which may improve the interpretability and comparability of future research.

Prevalence of noncardiac findings in patients undergoing cardiac magnetic resonance imaging

Purpose. We sought to determine the prevalence of clinically significant non-cardiac abnormalities found in pediatric and adult patients undergoing cardiac magnetic resonance imaging (CMRI), and understand the impact of age on it's occurrence. Methods. We retrospectively reviewed all patients undergoing CMRI between May 2004 and July 2007. Findings were considered significant if they required radiographic or clinical follow-up. Results. A total of 408 patients underwent CMRI during the study period. Twenty two (16%) pediatric patients (age < 19 years, n = 135) were found to have a total of 22 non- cardiac abnormalities, 3 of which were clinically significant. Sixty four (23%) adult patients (age > 19 years, n = 273) were found to have a total of 77 non-cardiac abnormalities, 33 of which were clinically significant. The prevalence of clinically significant non-cardiac abnormalities was 2% in the pediatric cohort and 11% in the adult cohort (P = 0.05). Within the adult population, the prevalence of significant non-cardiac abnormalities increased with advancing age (P = 0.05). Conclusions. In a population of unselected patients undergoing CMRI, unanticipated noncardiac abnormalities were frequently seen. A small number of these were significant, with the prevalence increasing with age.

Prevalence and clinical significance of collateral findings detected by chest computed tomography in patients undergoing atrial fibrillation ablation

AIMS

Chest computed tomography (CT) scanning is increasingly used as an imaging technique in patients undergoing atrial fibrillation (AF) catheter ablation. Chest CT scans visualize organs other than the heart and collateral findings may be identified incidentally. Our study aims to assess the prevalence and clinical relevance of such collateral findings in patients undergoing AF ablation.

METHODS AND RESULTS

One hundred and seventy-three patients (127 males, age 59 ± 10 years) underwent chest CT scan for image integration in AF ablation. Collateral findings from visualized thoracic and upper abdominal organs were collected. Findings that required further investigations or treatment according to current guidelines were considered as clinically significant. A total of 164 collateral findings were identified in 97 (56%) patients, and most patients showed abnormalities of the lungs (67 patients, 39%). Forty-nine (28%) patients had clinically significant findings needing further investigation and 17 (10%) of them required specific treatments, including three cases (1.7 %) of lung malignancy.

CONCLUSIONS

Chest CT images acquired for integration in AF ablation should be read thoroughly as they may serve as a screening tool for otherwise unrecognized clinically significant conditions of the heart, lungs, or other visualized organs.

Incidental extracardiac findings in cardiac computed tomography performed before radiofrequency ablation of atrial fibrillation

BACKGROUND

Radiofrequency ablation has became a validated therapeutic technique for symptomatic drug refractory atrial fibrillation (AF). Cardiac computed tomography (CT) is used to evaluate left atrial (LA) anatomy in order to improve AF ablation. The analysis of noncardiac structures during cardiac CT may identify clinically significant incidental findings (IFs). The objective of this study was to determine the prevalence of IF in patients undergoing AF catheter ablation.

METHODS

Between February 2008 and March 2010, all patients planned for a first procedure of AF or LA tachycardia (LAT) ablation underwent a cardiac CT scan and were retrospectively included in this study. Extracardiac IFs were considered to be present if an abnormality was identified without previous clinical suspicion or known disease.

RESULTS

Two hundred and fifty patients (55.2 ± 9.6 years of age, 82.4% men) were enrolled (133 paroxysmal, 43 persistent, 58 permanent AF, and 16 LAT). Fifty-eight patients (23.2%) had a total of 76 IFs. Patients with IF were significantly older (59.5 ± 8.2 vs 53.8 ± 9.7 years old, P < 0.001). No relationship existed between the type of arrhythmia and IF existence. The majority of IFs were pulmonary (50%), with 15.8% of pulmonary emphysema. Two cases of lung cancer and of pulmonary fibrosis, 15 mediastinal adenopathies, and three congenital coronary arteries anomalies were found.

CONCLUSIONS

Cardiac CT scan is a useful tool to evaluate LA morphology before AF ablation. However, as a considerable prevalence of IF was found in our study, extracardiac structures should be routinely analyzed to detect unknown conditions, which could require specific management.

Clinically significant incidental findings among human immunodeficiency virus-infected men during computed tomography for determination of coronary artery calcium

Those infected with the human immunodeficiency virus (HIV) have a greater risk of cardiovascular disease and might undergo computed tomographic (CT) scans for early detection. Incidental findings on cardiac CT imaging are important components of the benefits and costs of testing. We determined the prevalence and factors associated with incidental findings on CT scans performed to screen for coronary artery calcium (CAC) among HIV-infected men. A clinically significant finding was defined as requiring additional workup or a medical referral. A total of 215 HIV-infected men were evaluated. Their median age was 43 years; 17% were current tobacco users; the median CD4 count was 580 cells/mm(3); and 83% were receiving antiretroviral medications. Also, 34% had a positive CAC score of >0. An incidental finding was noted among 93 participants (43%), with 36 (17%) having ≥1 clinically significant finding. A total of 139 findings were noted, most commonly pulmonary nodules, followed by granulomas, scarring, and hilar adenopathy. Most of the incidental findings were stable on follow-up, and no malignancies were detected. The factors associated with the presence of an incidental finding in the multivariate model included increasing age (odds ratio 1.6 per 10 years, p <0.01), positive CAC score (odds ratio 2.3, p <0.01), and current tobacco use (odds ratio 2.5, p = 0.02). In conclusion, incidental findings were common among HIV-infected men undergoing screening CT imaging for CAC determination. The incidental findings were more common among older patients and those with detectable CAC.

Incidental extracardiac findings at coronary CT: clinical and economic impact

OBJECTIVE

The purpose of this study was to evaluate the prevalence of incidental extracardiac findings on coronary CT, to determine the associated downstream resource utilization, and to estimate additional costs per patient related to the associated diagnostic workup.

MATERIALS AND METHODS

This retrospective study examined incidental extracardiac findings in 151 consecutive adults (69.5% men and 30.5% women; mean age, 54 years) undergoing coronary CT during a 7-year period. Incidental findings were recorded, and medical records were reviewed for downstream diagnostic examinations for a follow-up period of 1 year (minimum) to 7 years (maximum). Costs of further workup were estimated using 2009 Medicare average reimbursement figures.

RESULTS

There were 102 incidental extracardiac findings in 43% (65/151) of patients. Fifty-two percent (53/102) of findings were potentially clinically significant, and 81% (43/53) of these findings were newly discovered. The radiology reports made specific follow-up recommendations for 36% (19/53) of new significant findings. Only 4% (6/151) of patients actually underwent follow-up imaging or intervention for incidental findings. One patient was found to have a malignancy that was subsequently treated. The average direct costs of additional diagnostic workup were $17.42 per patient screened (95% CI, $2.84-$32.00) and $438.39 per patient with imaging follow-up (95% CI, $301.47-$575.31).

CONCLUSION

Coronary CT frequently reveals potentially significant incidental extracardiac abnormalities, yet radiologists recommend further evaluation in only one-third of cases. An even smaller fraction of cases receive further workup. The failure to follow-up abnormal incidental findings may result in missed opportunities to detect early disease, but also limits the short-term attributable costs.

Utility of radiologic review for noncardiac findings on multislice computed tomography in patients with severe aortic stenosis evaluated for transcatheter aortic valve implantation

Transcatheter aortic valve implantation (TAVI) without replacement requires precise knowledge of the anatomic dimensions and physical characteristics of the peripheral vasculature and aortic valve annulus at the insertion of the aortic valve leaflet and root at the level of the sinus of Valsalva. Multislice computed tomography (CT) allows detailed and precise assessment of the anatomic variables. Noncardiovascular structures are also amenable to assessment by CT. Of the 394 patients screened for TAVI, 259 (65.7%) had non-contrast CT to evaluate chest anatomy and contrast CT to evaluate ilio-femoral anatomy. Significant noncardiac findings were defined as those requiring immediate evaluation or intervention or additional clinical or radiologic follow-up. Noncardiovascular findings known before CT were not included. Of the 259 patients, 105 (40.5%) were men. The mean age was 82.3 +/- 8.1 years. New, significant noncardiovascular findings were found in 89 (34.3%) and malignancy in 11 (4.2%) patients. Insignificant noncardiovascular findings were identified in 222 patients (85.7%). Signs of fluid retention were noted on CT in 105 patients (40.5%), with pleural effusion in 100 (38.6%), ascites in 17 (6.5%), and pericardial effusion in 14 (5.4%). Important peripheral vascular disease was found in 98 patients (37.8%), resulting in exclusion of 49 (19.1%) from TAVI using the transfemoral approach. An aortic aneurysm was found in 10 patients (3.8%) and a "porcelain" aorta (heavily calcified ascending aorta) in 19 (7.3%). In conclusion, malignancy and other noncardiovascular abnormalities are often found in patients who undergo CT for evaluation for TAVI. Populations must be meticulously examined to ensure that important findings are not missed.

High-pitch electrocardiogram-triggered computed tomography of the chest: initial results

OBJECTIVES

Chest pain is one of the most frequent symptoms in the emergency department. A variety of different diseases, some of them acutely life threatening, can be the underlying cause. Electrocardiogram (ECG)-gated computed tomography angiography of the thorax has been proposed as a cost and time effective imaging technique for these patients. We describe a new high-pitch scan mode, which has been developed specifically for low-dose ECG-triggered computed tomography angiography using dual source computed tomography (CT).

MATERIAL AND METHODS

Twenty-four patients were examined with this technique on a second generation dual source CT system. The scan mode uses a pitch of 3.2 to acquire a spiral CT data set of the complete thorax in less than 1 second with a temporal resolution of 75 ms (scan parameters: 128 x 0.6 mm collimation, 0.28 seconds gantry rotation time, 370 mAs at 100 kV [15 patients] and 320 mAs at 120 kV [9 patients], reconstructed slice thickness 0.6 mm, increment 0.4 mm). Data acquisition was prospectively triggered at 50% to 60% of the RR interval to cover the range over the heart in diastole. A triple phase contrast injection protocol (total volume: 80 mL) was used to optimize enhancement of the pulmonary and systemic arterial vessels. Image quality was evaluated using a 4-point scale (1 = absence of motion artifacts; 2 = slight motion artifacts, fully evaluable; 3 = motion artifacts, but evaluable; 4 = unevaluable) on a per-segment basis.

RESULTS

The patients had an average heart rate of 68 +/- 15 bpm (range: 43-111 bpm) during data acquisition. Motion artifact free visualization of the aorta and pulmonary vessels was possible in each case, of 344 coronary artery segments, 242 (70%) had an image quality score of 1, 60 segments (17%) a score of 2, 28 segments (8%) a score of 3, and 14 segments (4%) were rated as "unevaluable." In 17 patients (10 patients with a heart rate < or =60 bpm) all segments were evaluable. The average dose length product was 113 +/- 11 mGy x cm per scan (mean effective dose 1.6 +/- 0.2 mSv) at 100 kV and 229 +/- 31 mGy x cm per scan (mean effective dose 3.2 +/- 0.4 mSv) at 120 kV.

CONCLUSION

Our initial results indicate that this high-pitch scan mode allows motion artifact free and accurate visualization of the thoracic vessels, and diagnostic image quality of the coronary arteries in patients with low and stable heart rates at a very low radiation exposure.

Incidental non-cardiac findings of a coronary angiography with a 128-slice multi-detector CT scanner: should we only concentrate on the heart?

Objective

To evaluate the spectrum, prevalence, and significance of incidental non-cardiac findings (INCF) in patients referred for a non-invasive coronary angiography using a 128-slice multi-detector CT (MDCT).

Materials and Methods

The study subjects included 1,044 patients; 774 males (mean age, 59.9 years) and 270 females (mean age, 63 years), referred for a coronary CT angiography on a 128-slice MDCT scanner. The scans were acquired from the level of the carina to just below the diaphragm. To evaluate INCFs, images were reconstructed with a large field of view (> 300 mm) covering the entire thorax. Images were reviewed in the axial, coronal, and sagittal planes, using the mediastinal, lung, and bone windows. The INCFs were classified as severe, indeterminate, and mild, based on their clinical importance, and as thoracic or abdominal based on their locations.

Results

Incidental non-cardiac findings were detected in 56% of patients (588 of 1,044), including 435 males (mean age, 65.6 years) and 153 females (mean age, 67.9 years). A total of 729 INCFs were observed: 459 (63%) mild (58% thoracic, 43% abdominal), 96 (13%) indeterminate (95% thoracic, 5% abdominal), and 174 (24%) severe (87% thoracic, 13% abdominal). The prevalence of severe INCFs was 15%. Two severe INCFs were histologically verified as lung cancers.

Conclusion

The 128-slice MDCT coronary angiography, in addition to cardiac imaging, can provide important information on the pathology of the chest and upper abdomen. The presence of severe INCFs is not rare, especially in the thorax. Therefore, all organs in the scan should be thoroughly evaluated in daily clinical practice.

Prevalence of non-cardiac findings in a large series of patients undergoing cardiac multi-detector computed tomography scans

The purpose of our study was to determine the prevalence of non-cardiac findings in a large series of patients undergoing contrast-enhanced cardiac multi-detector computed tomography (MDCT) scans. Non-cardiac findings were classified according to the organ of involvement and level of significance. We retrospectively reviewed scans and reports of 1,061 patients performed between 1 April 2004 and 31 April 2006. Non-cardiac findings were considered significant if they warranted further radiological or clinical follow-up. A total of 103 non-cardiac findings were reported in 85 (8.0%) of the 1,061 patients. Of these lesions, 48 (46.7%) were significant and 55 (53.3%) were not. The significant lesions were found in 33 of the 1,061 patients (3.1%). Among the significant abnormalities, the three most common were pulmonary nodules (16.7%), emphysema (16.7%) and possible hepatic carcinomas (12.6%). Patients with non-cardiac findings were significantly older than those without (mean age 60 +/- 6 years vs. 55 +/- 8 years; P < 0.0001). The prevalence of active smoking was significantly higher in patients with non-cardiac findings (28.2 vs. 17.8%; P = 0.03). The prevalence of non-cardiac abnormalities detected by cardiac MDCT was 8% and about half of these findings were deemed significant. These lesions commonly occurred in the lungs and the liver. Age and active smoking were predictive of the presence of non-cardiac abnormalities.

Clinical relevance and scope of accidental extracoronary findings in coronary computed tomography angiography: a cardiac versus thoracic FOV study

OBJECTIVE

To assess the spectrum and clinical relevance of extracoronary findings in coronary CT angiography (CCTA), and to compare a small (cardiac) field of view (FOV) to a large (thoracic) FOV setting.

MATERIAL AND METHODS

1084 consecutive patients (mean 57 years) with low-to-intermediate risk of coronary artery disease were enrolled. 542 CCTA scans were interpreted with small FOV (160-190mm(2)) encompassing the cardiac region. In another 542 CCTA (patients matched for age and gender), read-out of an additional full FOV (>320mm(2)) covering the thorax was performed. Clinical relevance of extracoronary findings was considered as either "significant" or "non-significant". "Significant" findings were subclassified as either score 1: findings necessitating immediate therapeutic actions, or score 2: findings with undoubted clinical or prognostic relevance, requiring clinical awareness, follow-up or further investigations (non-urgent). "Non-significant" findings were assigned to either score 3: findings not requiring follow-up or further tests, or as score 4: irrelevant incidental findings.

RESULTS

Significantly more patients with extracoronary findings were identified by using a full FOV with 43.2% (234/542) compared to a small FOV with 33.6% (182/542) (p=0.001). Similarly, a higher total number of extracoronary findings (n=394) was found on full FOV compared to small FOV (n=250) (p<0.001). The detection rate of clinically significant findings was higher by using full FOV compared to small FOV (25.6% versus 15.4%) (p<0.001), out of those 2.2% versus 1.8% of findings required immediate actions (score 1), and 23.4% versus 13.6% (p=0.0001), respectively were of clinical relevance (non-urgent, score 2). The rate of malign findings was 0.2%, and of acute pulmonary embolism 0.1%. More lung pathologies were observed by using full FOV compared to small FOV (22% versus 7%) (p<0.0001), and the detection rate of intrapulmonary nodules increased by 2.1%. Prevalence of aortic valve calcification (n=72) was 13.3%, out of those 7% had less than 2cm(2) aortic valve orifice area.

CONCLUSIONS

The interpretation of extracoronary findings on CCTA scans is mandatory given high prevalence of clinically significant findings by using a full "thoracic" FOV.

Incidental extracardiac findings at cardiac CT angiography: comparison of prevalence and clinical significance between precontrast low-dose whole thoracic scan and postcontrast retrospective ECG-gated cardiac scan

PURPOSE

To compare the prevalence and clinical significance of incidental extracardiac findings at cardiac CT angiography (CCTA) with precontrast low-dose whole thoracic scan (LDCT) and ECG-gated CCTA.

MATERIALS AND METHODS

We reviewed 254 patients who underwent CCTA. All participants first underwent LDCT to determine a range for CCTA and to screen unrecognized extracardiac lesions. CCTA was reconstructed with a small field of view of the heart. Clinically significant extracardiac findings were defined as abnormalities requiring further diagnostic work up, therapeutic intervention, or follow-up.

RESULTS

On LDCT, 285 extracardiac findings were detected in 62.6% patients; on CCTA, 18 findings in 7% patients. Among these, 66 findings in 20.4% patients were considered clinically significant on LDCT, and 4 findings in 1.6% patients on CCTA.

CONCLUSION

Clinically significant extracardiac findings are common in patients undergoing CCTA with a considerable number of extracardiac findings being detected only on LDCT. We advise performing whole thorax LDCT prior to CCTA.

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.