The prevalence of extracardiac findings by multidetector computed tomography before atrial fibrillation ablation

Incidental Cardiac Computed Tomography Findings in Patients Undergoing Atrial Fibrillation Catheter Ablation

Background: Catheter ablation (CA) is an effective technique for the management of atrial fibrillation (AF). Cardiac computed tomography (CCT) is a non-invasive imaging modality that is used as a crucial part of planning before CA procedures which can detect other incidental findings and require further diagnostic investigations.

Objectives: We sought to assess the prevalence and distribution of incidental CCT findings in patients with AF undergoing CA.

Methods: Retrospective analysis over a three-year period (2013-2016) of 218 patients undergoing CCT prior to AF CA. CCT findings were analyzed and incident clinically important findings were reported.

Results: Over the three-year period, 218 patients had undergone CCT. Of these, 28.8% showed clinically significant incidental findings in the chest and upper abdomen. Incidental findings included coronary artery disease (CAD), incomplete cor triatriatum, pericardial effusion, pleural effusion, pulmonary nodules, pulmonary infiltrates, pulmonary mass, thoracic aortic aneurysm, mediastinal nodes, abdominal mass, and liver nodules.

Conclusions: CCT is a cornerstone investigation prior to AF CA and can show multiple incidental findings, thus potentially functioning as a screening method for the detection of other significant conditions. There is still a debate whether further workup is needed or not as most findings will eventually be benign and further investigations could mean financial burden and clinical risks to the patients. Further larger prospective studies are needed with long-term follow-up to determine whether incidental findings on CCT have an impact on the long-term outcomes of patients.

Extracardiac findings on cardiac computed tomography in patients undergoing atrial fibrillation catheter ablation

Abstract Background and Aim

To assess the prevalence of incidental extracardiac findings in patients who underwent cardiac CT for the evaluation of left atrial (LA) anatomy before atrial fibrillation (AF) catheter ablation. We also aimed to determine the independent predictors of relevant extracardiac alterations.

Patients and Methods

We studied consecutive patients who underwent cardiac CT with a 256-slice scanner for the visualization of LA anatomy before AF ablation. Prevalence of clinically significant and not significant extracardiac findings were recorded. Moreover, we determined the variables associated with relevant extracardiac alterations with uni- and multivariate logistic regression analyses.

Results

In total, 1,952 consecutive patients who underwent cardiac CT examination between 2010 and 2020 were included in our study (mean age 61.2±10.6 years; 66.2% male). Incidental extracardiac findings were detected in 820 (42.0%; 95%CI=0.40-0.44%) patients, while clinically significant alterations were reported in 416 (21.3%; 95%CI=20.0-23.2%) patients. When analyzing the predictors of clinically relevant alterations, age (OR=1.04; 95%CI=1.03- 1.05), male sex (OR=1.39; 95%CI=1.12-1.73), chest pain (OR=1.46; 95%CI=1.09-1.93), hypertension (OR=1.42; 95%CI=1.12-1.81), heart failure (OR=1.68; 95%CI=1.09-2.53), obstructive CAD (OR=1.56; 95%CI=1.16-2.09) and prior stroke/TIA (OR=1.56; 95%CI=1.04- 2.30) showed association with clinically significant incidental findings in the univariate analysis (all p<0.05). In the multivariate analysis, age (OR=1.04; 95%CI=1.02-1.06; p<0.001) proved to be the only significant predictor of clinically relevant extracardiac finding.

Conclusion

Cardiac CT performed before AF ablation is not only helpful in understanding LA anatomy, but might also identify clinically significant pathologies. These incidental findings might have further diagnostic or therapeutic consequences.

Major incidental findings on routine cardiovascular magnetic resonance imaging prior to first-time catheter ablation of atrial fibrillation

Introduction

Preprocedural cardiovascular magnetic resonance (CMR) or computed tomography (CT) imaging of the left atrium/pulmonary veins is usually employed to guide catheter ablation of atrial fibrillation (AFCA). Incidental findings (IFs) are common on cardiac imaging prior to AFCA. However, previous studies have mainly focused on extracardiac IFs detected on CT scan. We aimed to assess the prevalence of relevant cardiac and extracardiac IFs on routine preprocedural CMR in a large patient cohort scheduled for first-time AFCA and report its impact on clinical decision-making and management.

Methods and results

We included 2000 consecutive patients (62 ± 10 years; 59% male) who underwent CMR prior to first-time AFCA between April 2015 and March 2019. Among these patients 172 (8.6%) had a total of 184 major IFs. Detection of major IFs resulted in cancellation of the scheduled AFCA procedure in 88 patients (4.4%). Forty-two patients (2.1%) have never been ablated, 46 (2.3%) underwent postponed AFCA after a median time of 83 (32–213) days. The remaining 84 patients (4.2%) underwent an individualized approach to AFCA. The most common major IFs were accessory or anomalous PVs in 76 (3.8%), extracardiac abnormalities suspicious of malignancy in 29 (1.5%), and positive stress perfusion imaging in 19 (7.2% of 261 tested) patients. In 19 patients (1.0%) preprocedural CMR provided the diagnosis of a previously unknown structural cardiac disease.

Conclusions

Unexpected relevant findings on routine preprocedural CMR affected clinical decision-making and management in 8.6% of patients scheduled for first-time AFCA. However, whether preprocedural CMR imaging may improve overall clinical outcome needs to be addressed in future research.

Screening of extravascular findings in pulmonary embolism computer tomography: 397 patients with 1950 non-pulmonary artery findings

Objectives

The aim of this study was to investigate the possible benefits from computed tomography scans of patients with a suspected pulmonary artery embolism with a focus on relevant extravascular findings.

Methods

A total of 400 consecutive computed tomography pulmonary angiographies were evaluated. Computed tomography scans were analyzed in detail for the presence of pulmonary artery embolisms, as well as any other findings. Extra-artery discoveries were classified into none-relevant (Group A), intermediate (Group B), or relevant (Group C) findings.

Results

Aggregated computed tomography pulmonary angiographies detected other diagnosis than pulmonary artery embolism in 236 patients (59%). There were 1950 non-pulmonary artery embolism findings (4.9 per patient; n = 397). In the pulmonary artery embolism group, there were 447 extra-pulmonary artery embolism findings (5.2 per patient; n = 86) and in the non-pulmonary artery embolism group, 1503 findings (4.8 per patient; n = 311). Patients with pulmonary artery embolism had a significantly higher rate of pro-coagulate risk factors ( p < 0.001).

Conclusions

Computed tomography pulmonary angiographies may help to identify further diagnoses. This study represents a retrospective review of a single center experience for incidental computed tomography findings during pulmonary artery embolism work-up and emphasizes the importance of analyzing the whole field-of-view.

Extra-vascular findings in patients undergoing magnetic resonance angiography of the abdomen, pelvis and lower extremities: A retrospective study of 352 patients

Background

The aim of this study was to assess the prevalence and clinical significance of extra-vascular findings in patients undergoing magnetic resonance angiography of the abdomen, pelvis and lower extremities.

Materials and methods

Three hundred fifty-two patients underwent abdominal, pelvic and lower extremity 1.5 T magnetic resonance angiography. Clinically relevant vascular and extra-vascular findings were identified. Relevant vascular findings were classified as stenosis, occlusion, aneurysm, sclerosis, dissection or vasculitis. Relevant extra-vascular findings were categorized as ‘safe’ (Group A), intermediate – requiring additional investigation – (Group B) and malignant/endangering – requiring change of therapy (Group C).

Results

A total of 2152 clinically relevant vascular findings was identified (6.1/patient). The most frequent vascular finding was femoral artery stenosis (10.6%). Four hundred fifty-one extra-vascular findings were observed (1.3/patient) and classified into Group A (78%), Group B (19.5%) and Group C findings (2.4%). The most frequent malignant findings were lung cancer, lymphoma, osteosarcoma, hepatocellular carcinoma and renal cell carcinoma (7/352 patients).

Conclusions

Extravascular findings are frequently encountered in magnetic resonance angiography performed for vascular indications. Clinically relevant findings are seen in a substantial part of patients and should prompt further diagnostic work-up.

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.

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.

A free-response evaluation determining value in the computed tomography attenuation correction image for revealing pulmonary incidental findings: a phantom study

RATIONALE AND OBJECTIVES

The purpose of this study was to compare lesion-detection performance when interpreting computed tomography (CT) images that are acquired for attenuation correction when performing single photon emission computed tomography/computed tomography (SPECT/CT) myocardial perfusion studies. In the United Kingdom, there is a requirement that these images be interpreted; thus, it is necessary to understand observer performance on these images.

MATERIALS AND METHODS

An anthropomorphic chest phantom with inserted spherical lesions of different sizes and contrasts was scanned on five different SPECT/CT systems using site-specific CT protocols for SPECT/CT myocardial perfusion imaging. Twenty-one observers (0-4 years of CT experience) searched 26 image slices (17 abnormal, containing 1-3 lesions, and 9 normal, containing no lesions) for each CT acquisition. The observers marked and rated perceived lesions under the free-response paradigm. Four analyses were conducted using jackknife alternative free-response receiver operating characteristic (JAFROC) analysis: (1) 20-pixel acceptance radius (AR) with all 21 readers, abbreviated to 20/ALL analysis, (2) 40-pixel AR with 21 readers (40/ALL), (3) 20-pixel AR with 14 readers experienced in CT (20/EXP), and (4) 20-pixel AR with 7 readers with no CT experience (20/NOT). The significance level of the test was set so as to conservatively control the overall probability of a type I error to <0.05.

RESULTS

The mean JAFROC figure of merit (FOM) for the five CT acquisitions for the 20/ALL study were 0.602, 0.639, 0.372, 0.475, and 0.719 with a significant difference in lesion-detection performance evident between all individual treatment pairs (P < .0001) with the exception of the 1-2 pairing, which was not significant (these differed only in milliamp seconds). System 5, which had the highest performance, had the smallest slice thickness and the largest matrix size. For the other analyses, the system orderings remained unchanged, and the significance of FOM difference findings remained identical to those for 20/ALL, with one exception: for 20/EXP analysis the 1-2 difference became significant with the higher milliamp seconds superior. Improved detection performance was associated with a smaller slice thickness, increased matrix size, and, to a lesser extent, increased tube charge.

CONCLUSIONS

Protocol variations for CT-based attenuation correction (AC) in SPECT/CT imaging have a measurable impact on lesion-detection performance. The results imply that z-axis resolution and matrix size had the greatest impact on lesion detection, with a weaker but detectable dependence on the product of milliamp and seconds.

Malignant incidental extracardiac findings on cardiac CT: systematic review and meta-analysis

OBJECTIVE

The objective of our study was to systematically review the evidence on incidental extracardiac findings on cardiac CT with a focus on previously unknown malignancies.

MATERIALS AND METHODS

A systematic search was performed (PubMed, EMBASE, Cochrane databases) for studies reporting incidental extracardiac findings on cardiac CT. Among 1099 articles initially found, 15 studies met the inclusion criteria. The references of those articles were hand-searched and 14 additional studies were identified. After review of the full text, 10 articles were excluded. Nineteen studies including 15,877 patients (64% male) were analyzed. A three-level analysis was performed to determine the prevalence of patients with incidental extracardiac findings, the prevalence of patients with major incidental extracardiac findings, and the prevalence of patients with a proven cancer. Heterogeneity was explored for multiple variables. Pooled prevalence and 95% CI were calculated.

RESULTS

The prevalence of both incidental extracardiac findings and major incidental extracardiac findings showed a high heterogeneity (I2>95%): The pooled prevalence was 44% (95% CI, 35-54%) and 16% (95% CI, 14-20%), respectively. No significant explanatory variables were found for using or not using contrast material, the size of the FOV, and study design (I2>85%). The pooled cancer prevalence for 10 studies including 5082 patients was 0.7% (95% CI, 0.5-1.0%), with an almost perfect homogeneity (I2<0.1%). Of 29 reported malignancies, 21 (72%) were lung cancers; three, thyroid cancers; two, breast cancers; two, liver cancers; and one, mediastinal lymphoma.

CONCLUSION

Although the prevalence of reported incidental extracardiac finding at cardiac CT was highly variable, a homogeneous prevalence of previously unknown malignancies was reported across the studies, for a pooled estimate of 0.7%; more than 70% of these previously unknown malignancies were lung cancers. Extracardiac findings on cardiac CT require careful evaluation and reporting.

The incidence, pattern, and prognostic value of left ventricular myocardial scar by late gadolinium enhancement in patients with atrial fibrillation

OBJECTIVES

This study sought to identify the frequency, pattern, and prognostic significance of left ventricular (LV) late gadolinium enhancement (LGE) in patients with atrial fibrillation (AF).

BACKGROUND

There are limited data on the presence, pattern, and prognostic significance of LV myocardial fibrosis in patients with AF. LGE during cardiac magnetic resonance imaging is a marker for myocardial fibrosis.

METHODS

A group of 664 consecutive patients without known prior myocardial infarction who were referred for radiofrequency ablation of AF were studied. Cardiac magnetic resonance imaging was requested to assess pulmonary venous anatomy.

RESULTS

Overall, 73% were men, with a mean age of 56 years and a mean LV ejection fraction of 56 ± 10%. LV LGE was found in 88 patients (13%). The endpoint was all-cause mortality, and in this cohort, 68 deaths were observed over a median follow-up period of 42 months. On univariate analysis, age (hazard ratio [HR]: 1.05; 95% confidence interval [CI]: 1.03 to 1.08; chi-square likelihood ratio [LRχ(2)]: 15.2; p = 0.0001), diabetes (HR: 2.39; 95% CI: 1.41 to 4.09; LRχ(2): 10.3; p = 0.001), a history of heart failure (HR: 1.78; 95% CI: 1.09 to 2.91; LRχ(2): 5.37; p = 0.02), left atrial dimension (HR: 1.04; 95% CI: 1.01 to 1.08; LRχ(2): 6.47; p = 0.01), presence of LGE (HR: 5.08; 95% CI: 3.08 to 8.36; LRχ(2): 28.8; p < 0.0001), and LGE extent (HR: 1.15; 95% CI: 1.10 to 1.21; LRχ(2): 35.6; p < 0.0001) provided the strongest associations with mortality. The mortality rate was 8.1% per patient-year in patients with LGE compared with 2.3% patients without LGE. In the best overall multivariate model for mortality, age and the extent of LGE were independent predictors of mortality. Indeed, each 1% increase in the extent of LGE was associated with a 15% increased risk for death.

CONCLUSIONS

In patients with AF, LV LGE is a frequent finding and is a powerful predictor of mortality.

Prevalence and clinical relevance of extracardiac findings at cardiac MRI

PURPOSE

To assess the incidence of extracardiac findings in patients undergoing clinical cardiac magnetic resonance imaging (CMRI) of the heart, and to determine the influence of those findings on patient management.

MATERIALS AND METHODS

During 40 months, 854 CMRI were performed at 1.5 T. Extracardiac findings were classified as significant (group A), if recommended for additional diagnostics or therapeutic interventions, and as nonsignificant (group B).

RESULTS

The most frequent indication for CMRI was evaluation of cardiac stress ischemia. In all, 631 CMRI (74% of 854) showed no extracardiac pathologies. In the remaining 223 CMRI (26% of 854), a total of 286 extracardiac findings were detected. Among these findings, 49 were considered significant (group A) and 237 nonsignificant (group B). In group A, the most common findings were suspicious pulmonary nodules or masses. In group B, the most frequent findings were hepatic cysts or hemangiomas. Eight malignancies were observed with certainty at CMRI. Seven of them had been incidentally diagnosed on CMRI for the first time, and subsequently changed the patients' management.

CONCLUSION

Extracardiac findings in clinically indicated CMRI are common (about 26%). Radiologists and cardiologists should be aware of relevant extracardiac findings that might require additional diagnostics or treatment.

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.

Role of echocardiography in atrial fibrillation

Atrial fibrillation (AF) is most common arrhythmia and its prevalence appears to be increasing as the population ages. Echocardiography can play a key role in risk stratification and management of patients with AF. Transthoracic echocardiography allows rapid and comprehensive assessment of cardiac anatomical structure and function. Pulmonary vein flow monitoring using echocardiography has the potential to an increasing role in the evaluation of cardiac function and AF ablation procedures. Transesophageal echocardiography also provides accurate information about the presence of a thrombus in the atria and thromboembolic risk. The novel technique of intracardiac echocardiography has emerged as a popular and useful tool in the everyday practice of interventional electrophysiology. Other imaging modalities, such as computed tomography and magnetic resonance imaging have complementary roles in risk stratification and assessment of patients with AF. Echocardiography continues to be the foundation of clinical evaluation and management of AF.

Extra cardiac findings by 64-multidetector computed tomography in patients with symptomatic atrial fibrillation prior to pulmonal vein isolation

The aim of this study was to investigate the prevalence of extracardiac findings diagnosed by 64-multidetector computed tomography (MDCT) examinations prior to circumferential pulmonary vein (PV) ablation of atrial fibrillation (AF). A total of 158 patients (median age, 60.5 years; male 68%) underwent 64-MDCT of the chest and upper abdomen to characterize left atrial and PV anatomy prior to AF ablation. MDCT images were evaluated by a thoracic radiologist and a cardiologist. For additional scan interpretation, bone, lung, and soft tissue window settings were used. CT scans with extra-cardiac abnormalities categorized for the anatomic distribution and divided into two groups: Group 1—exhibiting clinically significant or potentially significant findings, and Group 2—patients with clinically non-significant findings. Extracardiac findings (n = 198) were observed in 113/158 (72%) patients. At least one significant finding was noted in 49/158 patients (31%). Group 1 abnormalities, such as malignancies or pneumonias, were found in 85/198 findings (43%). Group 2 findings, for example mild degenerative spine disease or pleural thickening, were observed in 113/198 findings (72%). 74/198 Extracardiac findings were located in the lung (37%), 35/198 in the mediastinum (18%), 8/198 into the liver (4%) and 81/198 were in other organs (41). There is an appreciable prevalence of prior undiagnosed extracardiac findings detected in patients with AF prior to PV-Isolation by MDCT. Clinically significant or potentially significant findings can be expected in ~40% of patients who undergo cardiac MDCT. Interdisciplinary trained personnel is required to identify and interpret both cardiac and extra cardiac findings.

Lung cancer detected at cardiac CT: prevalence, clinicoradiologic features, and importance of full-field-of-view images

PURPOSE

To retrospectively evaluate the prevalence and clinicoradiologic features of lung cancer detected at cardiac computed tomography (CT) and compare the detection rates at different field-of-view (FOV) settings.

MATERIALS AND METHODS

The institutional review board approved this retrospective study and waived the requirement for patient consent. Patients with lung cancer initially detected at cardiac CT were identified by means of a retrospective search of a lung cancer registry patient database between January 2004 and December 2007. Patients known to have lung cancer at the time of cardiac CT were excluded. The prevalence and clinical and radiologic features of lung cancer were evaluated. The rates of lung cancer detection at three FOVs-limited and full FOV at cardiac scanning and full FOV at thoracic scanning-were compared by using McNemar testing.

RESULTS

The prevalence of lung cancer detected at CT was 0.31% (36 of 11654 patients, 16 [44%] never smokers) and was higher in patients suspected or known to have coronary artery disease (0.43% [24 of 5615 patients]) than in asymptomatic screening-examined patients (0.20% [12 of 5924 patients]) (P = .0457). Adenocarcinoma was the most common (in 31 [86%] of 36 patients) histologic subtype. Of 34 non-small cell lung cancers, 23 (68%)-including 16 stage IA cancers-were resectable. Four (11%) and 19 (53%) of the 36 CT-depicted cancers were visible in limited and full FOV at cardiac scanning, respectively, and 17 (47%) were visible in full FOV at thoracic scanning only.

CONCLUSION

The prevalence of lung cancer at cardiac CT was 0.31%; and 68% of these malignancies were at a resectable stage. Use of a limited FOV at cardiac scanning led to a large majority (89% [32 of 36 cancers]) of the lung cancers detected at full thoracic scanning being missed; thus, inclusion of the entire chest at cardiac CT is advisable.

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.

Extra-cardiac findings at cardiac CT: experience with 1,764 patients

To investigate incidental extra-cardiac findings (ECF) at cardiac CT based on indication and impact on patient management. We retrospectively reviewed the reports of 1,764 patients who underwent a cardiac CT study between January 1, 2004 and December 31, 2006, including 463 calcium scorings (CS), 737 coronary CT angiograms (CTA), 341 pulmonary vein stenoses (PVS), and 223 bypass grafts (CABG). ECFs were categorized by type of examination, anatomical location and clinical significance. Comparisons were made between examination types to determine if incidental findings varied by indication. There were 507 ECFs with at least one ECF in 441 patients (25.0%). By examination, there was at least 1 ECF in 79/463 CS studies (17.1%), 196/737 CTAs (26.6%), 80/341 PVSs (23.4%) and 86/223 CABGs (38.6%). In 325 patients (18.4%), the findings were considered clinically important and occurred in 60/463 (12.9%) CSs, 149/737 (20.2%) CTAs, 56/341 (16.4%) PVSs and 60/223 (26.9%) CABGs. Differences between CABG and other indications and CTA vs. CS for incidental and clinically important findings were statistically significant (p < 0.05). Extra-cardiac findings requiring follow-up occur in 18% of patients and are significantly more frequent in coronary artery CTA and coronary artery bypass studies than in calcium scoring studies.

SPECT/CT

In view of the commercial success of integrated PET/CT scanners, there is an increasing interest in comparable SPECT/CT systems. SPECT in combination with CT enables a direct correlation of anatomic information and functional information, resulting in better localization and definition of scintigraphic findings. Besides anatomic referencing, the added value of CT coregistration is based on the attenuation correction capabilities of CT. The number of clinical studies is limited, but pilot studies have indicated a higher specificity and a significant reduction in indeterminate findings. The superiority of SPECT/CT over planar imaging or SPECT has been demonstrated in bone scintigraphy, somatostatin receptor scintigraphy, parathyroid scintigraphy, and adrenal gland scintigraphy. Also, rates of detection of sentinel nodes by biopsy can be increased with SPECT/CT. This review highlights recent technical developments in integrated SPECT/CT systems and summarizes the current literature on potential clinical uses and future directions for SPECT/CT in cardiac, neurologic, and oncologic applications.