this retrospective study included 1,044 patients ( 774 males , mean age of 59.9 years and 270 females , mean age of 63.0 years ) referred for ccta , between february 2008 to march 2009 . the indications for ccta were an abnormal , equivocal or non - diagnostic stress test , chest pain , evaluation of cardiomegaly and congestive heart failure , as well as the evaluation of cardiac aetiology of syncope . patients with a intermediate probability of coronary artery disease ( cad ) were also referred for a ccta as a first test . the above are considered appropriate indications for ccta , based on the criteria of the american college of cardiology ( acc ) ( 12 ) and the recent american heart association scientific statement on cardiac ct ( 13 ) . exclusion criteria for ccta included the presence of multiple ectopic beats , atrial fibrillation , renal failure , and a history of allergic reaction to iodine - containing contrast agents . smoking was the most frequent risk factor for cad ( 72% ) , followed by hypertension ( 68% ) , hyperlipidemia ( 60% ) , and diabetes mellitus ( 11% ) . the pre - test probability of cad was defined based on clinical symptoms , age , and gender according to the diamond and forrester classification ( 14 ) . of the 1,044 patients analyzed , 279 ( 27% ) had a low probability ( < 30% ) and 765 ( 73% ) had an intermediate probability ( 30 - 70% ) of cad . there were no high - risk patients for cad in this study , as they were referred directly for a conventional coronary angiography . coronary ct angiography examinations were performed on a 128-slice mdct ( definition as plus 128 , siemens , germany ) using retrospective electrocardiographic ( ecg ) gating with the following parameters : 128  0.6 collimation , 0.3 sec rotation time , pitch of 0.32 , 120 kv tube voltage and 185 reference mas . patients with heart rates over 75 bpm with no contraindications to the use of beta - blockers received metoprolol orally 1 hour before the examination to reduce heart rate . image acquisition was performed during inspiratory breath - hold . to familiarize the patient with the protocol , breath - holding was practiced before the examination . the ccta protocol was the following : at the beginning of the examination , a non - contrast localization scan was performed to plan the scan volume . the acquisition delay time was determined by injection of 20 ml test - bolus at 5 ml / sec . the peak time of test - bolus enhancement was used as a delay time . a non - ionic contrast medium ( iomeron 400 mg iodine / ml ; bracco altana pharma , germany ) the total contrast dosage for the ccta was adapted to the calculated scan duration ( 5 ml / sec + 5 ml , total 65 - 80 ml , infusion rate 5.0 ml / sec , saline bolus 50 ml , flow 5 ml / sec ) . patients were scanned in the supine position twice , first without contrast medium to calculate the calcium score and secondly after contrast medium injection . studies were acquired in the cranio - caudal direction from the level of the carina to just below the diaphragm . images were reconstructed at an effective slice thickness of 0.6 mm and a retrospective ecg gating at 10% steps throughout the cardiac cycle . the best mid - late systolic ( 20 - 40% of rr - interval ) or mid - late diastolic ( 50 - 70% of rr - interval ) data set was chosen for final image interpretation . to evaluate the coronary arteries , the images were reconstructed with a small fov ( 120 - 190 mm ) , which was restricted to the heart region and a medium - smooth convolution kernel ( b 26f ) . additionally , for the evaluation of incfs , images were reconstructed with a large fov ( > 300 mm ) at an effective slice thickness of 0.6 mm , from the outer rib to outer rib covering the entire thorax . the images were reviewed in the axial , coronal , and sagittal planes , using a mediastinal window ( width : 450 , level : 35 ) , lung window ( width : 1,500 , level : -700 ) , and bone window ( width : 1,500 , level : 450 ) for all examinations . each ct examination was retrospectively reviewed by two experienced radiologists in consensus and the incfs were reported . incidental non - cardiac findings were classified as thoracic , when located above the diaphragm and abdominal , when located below the diaphragm . incfs were also classified according to their clinical significance as severe , indeterminate , and mild . indeterminate findings were those of potential clinical importance , requiring a follow - up study or correlation with the patient 's history . finally , mild findings were those considered to be of little clinical significance with no further need of follow - up . further work - up of patients after ccta detection of indeterminate and severe incfs is described in figure 1 . for several smooth non - enhancing water attenuation lesions of the liver were described as liver cysts . nodular peripherally enhancing smooth liver lesions were characterized as haemangiomas . for the thoracic findings , pulmonary nodules were characterized based on their size , according to the current fleischner criteria ( 16 ) . however , if the nodules were found to be smaller than 8 mm , but with other imaging characteristics to suggest malignancy , they were classified as severe . areas with increased attenuation in lung parenchyma were characterized as consolidations or ground glass opacities , and low attenuation areas as emphysema . a diagnosis of interstitial lung disease was given when interlobular septal thickening was present in the absence of findings of congestive heart failure . an aortic diameter at the level of the ascending aorta of > 4 cm was considered aneurysmal , while for the abdominal aorta a diameter of > 3.5 cm was considered aneurysmal . the diagnosis of pulmonary embolization was based on the presence of filling defects in the pulmonary arteries and the diagnosis of pulmonary hypertension on the presence of dilated pulmonary arteries . for the lymphadenopathy , this retrospective study included 1,044 patients ( 774 males , mean age of 59.9 years and 270 females , mean age of 63.0 years ) referred for ccta , between february 2008 to march 2009 . the indications for ccta were an abnormal , equivocal or non - diagnostic stress test , chest pain , evaluation of cardiomegaly and congestive heart failure , as well as the evaluation of cardiac aetiology of syncope . patients with a intermediate probability of coronary artery disease ( cad ) were also referred for a ccta as a first test . the above are considered appropriate indications for ccta , based on the criteria of the american college of cardiology ( acc ) ( 12 ) and the recent american heart association scientific statement on cardiac ct ( 13 ) . exclusion criteria for ccta included the presence of multiple ectopic beats , atrial fibrillation , renal failure , and a history of allergic reaction to iodine - containing contrast agents . smoking was the most frequent risk factor for cad ( 72% ) , followed by hypertension ( 68% ) , hyperlipidemia ( 60% ) , and diabetes mellitus ( 11% ) . the pre - test probability of cad was defined based on clinical symptoms , age , and gender according to the diamond and forrester classification ( 14 ) . of the 1,044 patients analyzed , 279 ( 27% ) had a low probability ( < 30% ) and 765 ( 73% ) had an intermediate probability ( 30 - 70% ) of cad . there were no high - risk patients for cad in this study , as they were referred directly for a conventional coronary angiography . coronary ct angiography examinations were performed on a 128-slice mdct ( definition as plus 128 , siemens , germany ) using retrospective electrocardiographic ( ecg ) gating with the following parameters : 128  0.6 collimation , 0.3 sec rotation time , pitch of 0.32 , 120 kv tube voltage and 185 reference mas . patients with heart rates over 75 bpm with no contraindications to the use of beta - blockers received metoprolol orally 1 hour before the examination to reduce heart rate . image acquisition was performed during inspiratory breath - hold . to familiarize the patient with the protocol , breath - holding was practiced before the examination . the ccta protocol was the following : at the beginning of the examination , a non - contrast localization scan was performed to plan the scan volume . the acquisition delay time was determined by injection of 20 ml test - bolus at 5 ml / sec . the peak time of test - bolus enhancement was used as a delay time . a non - ionic contrast medium ( iomeron 400 mg iodine / ml ; bracco altana pharma , germany ) the total contrast dosage for the ccta was adapted to the calculated scan duration ( 5 ml / sec + 5 ml , total 65 - 80 ml , infusion rate 5.0 ml / sec , saline bolus 50 ml , flow 5 ml / sec ) . patients were scanned in the supine position twice , first without contrast medium to calculate the calcium score and secondly after contrast medium injection . studies were acquired in the cranio - caudal direction from the level of the carina to just below the diaphragm . images were reconstructed at an effective slice thickness of 0.6 mm and a retrospective ecg gating at 10% steps throughout the cardiac cycle . the best mid - late systolic ( 20 - 40% of rr - interval ) or mid - late diastolic ( 50 - 70% of rr - interval ) data set was chosen for final image interpretation . to evaluate the coronary arteries , the images were reconstructed with a small fov ( 120 - 190 mm ) , which was restricted to the heart region and a medium - smooth convolution kernel ( b 26f ) . additionally , for the evaluation of incfs , images were reconstructed with a large fov ( > 300 mm ) at an effective slice thickness of 0.6 mm , from the outer rib to outer rib covering the entire thorax . the images were reviewed in the axial , coronal , and sagittal planes , using a mediastinal window ( width : 450 , level : 35 ) , lung window ( width : 1,500 , level : -700 ) , and bone window ( width : 1,500 , level : 450 ) for all examinations . each ct examination was retrospectively reviewed by two experienced radiologists in consensus and the incfs were reported . incidental non - cardiac findings were classified as thoracic , when located above the diaphragm and abdominal , when located below the diaphragm . incfs were also classified according to their clinical significance as severe , indeterminate , and mild . indeterminate findings were those of potential clinical importance , requiring a follow - up study or correlation with the patient 's history . finally , mild findings were those considered to be of little clinical significance with no further need of follow - up . further work - up of patients after ccta detection of indeterminate and severe incfs is described in figure 1 . for several smooth non - enhancing water attenuation lesions of the liver were described as liver cysts . nodular peripherally enhancing smooth liver lesions were characterized as haemangiomas . for the thoracic findings , pulmonary nodules were characterized based on their size , according to the current fleischner criteria ( 16 ) . however , if the nodules were found to be smaller than 8 mm , but with other imaging characteristics to suggest malignancy , they were classified as severe . areas with increased attenuation in lung parenchyma were characterized as consolidations or ground glass opacities , and low attenuation areas as emphysema . a diagnosis of interstitial lung disease was given when interlobular septal thickening was present in the absence of findings of congestive heart failure . an aortic diameter at the level of the ascending aorta of > 4 cm was considered aneurysmal , while for the abdominal aorta a diameter of > 3.5 cm was considered aneurysmal . the diagnosis of pulmonary embolization was based on the presence of filling defects in the pulmonary arteries and the diagnosis of pulmonary hypertension on the presence of dilated pulmonary arteries . for the lymphadenopathy , the additional reconstructions performed for incf detection with a large fov , at three planes and three windows significantly increased the total time for reviewing each ccta examination . incfs were detected in 588 patients ( 56% ) ; 435 males ( mean age of 65.6 years ) and 153 females ( mean age of 67.9 years ) . in 135 patients ( 13% ) a total of 729 incfs were found : 459 ( 63% ) were classified as mild , 96 ( 13% ) as indeterminate and 174 ( 24% ) as severe . specifically , 305 of the 459 mild incfs ( 66% ) were detected in men ( mean age of 59.4 years ) , whereas the other 154 of the 459 ( 34% ) were found in women ( mean age of 59.9 years ) . moreover , 71 of the 96 indeterminate incfs ( 74% ) were detected in men ( mean age of 62.3 years ) , whereas 25 of the 96 ( 26% ) were found in women ( mean age of 64.1 years ) . finally , 133 of the 174 severe incfs ( 76% ) were detected in men ( mean age of 67.7 years ) , while 41 of the 174 ( 24% ) were found in women ( mean age of 69.1 years ) . the mild findings were 58% ( 264 of 459 ) thoracic and 43% ( 195 of 459 ) abdominal , while indeterminate findings were 95% ( 91 of 96 ) thoracic and 5% ( 5 of 96 ) abdominal . lastly , the severe findings were 87% ( 152 of 174 ) thoracic and 13% ( 22 of 174 ) abdominal . 2 ) , liver haemangioma , liver echinococcus cyst , calcified liver granuloma , and calcified splenic granuloma ( table 1 ) . mild thoracic findings included emphysema , calcified lung granuloma , bone haemangioma , bronchiectasis , hiatus hernia ( fig . 3 ) , calcified lymph nodes , remote fracture , and substernal thyroid ( table 1 ) . indeterminate thoracic findings included pulmonary nodules > 0.8 cm and < 3 cm , consolidation or ground glass opacities ( fig . 4 ) , pleural effusion , atelectasis , interstitial lung disease , pleural thickening , mediastinal mass lesions , and thoracic adenopathy ( table 2 ) . severe abdominal findings included liver masses and abdominal aortic aneurysms ( table 3 ) . 5 ) , dilated aortic root , pulmonary embolization , pulmonary hypertension , pulmonary nodules > 3 cm , and pulmonary nodules of any size with malignant characteristics ( table 3 ) . a comparison with previous radiological studies was available in a number of cases , but further follow - up was possible in a limited number of cases . in 10 patients , pulmonary nodules classified as indeterminate were known from previous thorax ct examinations . no change in size was detected within 2 or more years and the nodules were considered mild . in three of these patients , pleural thickening was also noted , which remained stable and was also considered mild . for the indeterminate and severe pulmonary nodules , either a follow - up with thorax ct or further evaluation via biopsy was recommended . a pathological verification was only available for 2 of the 9 pulmonary nodules > 3 cm , which proved to be malignant ( fig . all three patients with consolidation or ground glass opacities had mediastinal lymphadenopathy and received antibiotic therapy . a radiological follow - up with x - rays showed regression of the lung lesions . three patients with pleural effusions had a known history of congestive heart failure and the effusions existed in recent previous x - rays . overreading cardiac imaging examinations for the presence of incfs has been a subject of study , both with ct and mri techniques . several studies have reported the prevalence of incfs using electron - beam ct ( ebct ) . ( 17 ) studied 1,326 screening ebct examinations and found significant extra - cardiac pathology in 8% of the examinations . in a similar study of 1,812 ebct examinations , hunold although those findings included a number of clinically insignificant abnormalities , there was a need for the further testing of 9% of the 2,055 total extra - coronary findings . in the study by schragin et al . ( 19 ) 278 of 1,356 patients ( 21% ) undergoing ebct had one or more incfs . mckenna et al . ( 20 ) reported extra - cardiac findings in 107 of 132 ( 81% ) elderly patients ( mean age , 74 years ) undergoing a cardiac mri ; 63 of 131 ( 48% ) patients had multiple findings . a total of 224 incidental findings were visualized , including at least one potentially significant lesion in 23 of 135 ( 17% ) patients and one moderately significant finding in 43 of 129 ( 33% ) patients . mueller et al . ( 7 ) , who scanned patients with a 16-mdct scanner from the subclavian artery level , through the apex of the heart to asses graft patency after coronary artery bypass graft ( cabg ) surgery , found that 34 of 259 patients ( 13% ) had incfs , including pulmonary embolisms , lung cancer and pneumonia . dewey et al . ( 5 ) reported an incf incidence of 5% for clinically significant findings , and only 10% for non - significant findings in a cohort of 108 patients scanned with a 16-row mdct . however , gil et al . ( 9 ) reported extra - cardiac findings in 56% of the examined patients in their study , without classification by severity , in a cohort of 258 patients also scanned with a 16-row mdct . in the study of law et al . ( 10 ) with a 16-mcdt scanner , 56 out of 295 patients ( 19% ) had significant extra - coronary findings on cctas requiring clinical or radiological follow up . ( 8) reported a 58% prevalence of incfs among 503 patients referred for ccta using 16-slice and 64-slice mdct scanners . they found 23% of the patients with clinically significant non - cardiac pathology requiring additional work - up , and four cases ( 1% ) of malignancy . to our knowledge , this is the first study to report incfs from a ccta on a 128-slice mdct scanner . our study is also the first , to our knowledge , to include such a high number of patients examined with contrast medium - enhanced ccta . the significance of using a large fov , encompassing the entire thorax , versus a small fov , encompassing only the heart , during image reconstruction for evaluation of extra - cardiac structures , has been documented in previous reports . ( 21 ) studied the prevalence of extra - coronary findings using both a full " thoracic " fov and a small " cardiac " fov and found a higher detection rate of clinically significant findings by using the former compared to the latter ( 26% versus 15% ) ( p < 0.001 ) . ( 22 ) compared the frequency of detection of pulmonary nodules on cardiac ct scans acquired with a limited and a full fov , and concluded that viewing cardiac ct scans at a limited fov only can result in missing more than 67% of the nodules haller et al . ( 6 ) measured the volumes of the displayed body structures and found that 36% of the total chest volume was displayed on a dedicated ccta focused on the heart , whereas 70% of the chest was visible when the ccta raw data were reconstructed with a maximal field of view ( p < 0.001 ) . in our study , a small fov , restricted to the heart , was used for the evaluation of the coronary arteries and additional reconstruction of images with a large fov to encompass the entire thorax was performed in order to evaluate the presence of incfs . the necessity to look for incfs when practising cardiac imaging has been an issue of debate in the literature . in the study by budoff and gopal ( 11 ) , it is suggested that reanalyzing the data set for extra - cardiac disease would lead to additional costs and anxiety to the patient , while benefits have not yet been scientifically proven . ( 3 ) also stated that although recommendations for image reconstruction and training in the interpretation of incidental findings continue to evolve , ccta should be focused primarily on the coronary arteries . many studies , on the other hand , suggest that ccta scans can reveal important abnormalities in extra - cardiac structures contained in the scanned volume and therefore , the entire examination should be reconstructed with the maximum field of view and should be reviewed by qualified radiologists or cardiologists for the presence of incfs ( 4 , 6 - 10 , 15 ) . yiginer et al . ( 23 ) stated that it is controversial whether the incidental detection of non - cardiac pathology on coronary ct is an advantage , because additional diagnostic procedures with added costs may be needed . however , they suggest that the entire thorax should be scanned on calcium score imaging for smokers over 50 years in order to detect potentially malignant pulmonary nodules , because lung cancer is the most common fatal malignancy . kim et al . ( 24 ) report that it would be beneficial to include whole thorax low dose ct in the ccta protocol because it enables high - risk patients to undergo simultaneous screening for lung cancer and coronary artery disease with acceptable radiation exposure . however , the benefits of screening for lung cancer itself remain questionable ( 25 ) . while the detection of major abnormalities , like aortic dissection or pulmonary embolization is of obvious clinical importance , the 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 ( 3 ) . in a summary of the literature by colletti ( 26 ) on incidental findings detected with cardiac imaging , it is reported that it is likely that depending on the cohort , one in 100 to fewer than one in 1,000 patients may benefit from serendipitous discovery of extra - cardiac lesions . incidental findings will always be found in medical imaging , including ccta , and the decision of how to evaluate them as well as how to consult with the patients will continue to be an issue of discussion and probable debate . although the benefits of evaluating incfs have not been scientifically validated , we consider that the best approach is to view all available data in each ccta study , report all non - cardiac findings estimating their clinical significance , and consult each patient appropriately . specifically , the early detection of lung cancer is an issue of great importance ; in our study , two patients were diagnosed with lung cancer . accordingly , specialists who interpret cctas should be trained and qualified enough to recognize and evaluate extra - cardiac pathologies . the limitations of our study include the presence of limited follow - up data , as well as the absence of histopathological verification of indeterminate and most of severe incfs . in prior literature , limited follow - up data for incfs during cardiac imaging have been reported ( 5 , 8 - 10 ) . the proven outcome of incfs was reported in seven out of 617 cases in a study by kawano et al . ( 4 ) , three out of 166 cases in a study by haller et al . ( 6 ) , nine out of 259 cases in a study by mueller et al . ( 7 ) , and 15 out of 1,764 cases in a study by northam et al . in conclusion , a review of the available non - cardiac ccta data is advised , with the awareness that this may lead to further and sometimes unnecessary testing . the lungs , mediastinum , bones , and upper abdomen should be reviewed using appropriate mediastinal , bone , and lung windows and a large fov to include the entire thorax . patients should undergo clinical consultation based on the abnormalities seen in structures other than the coronary arteries during ccta .
objectiveto 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 methodsthe 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.resultsincidental 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.conclusionthe 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 .