aortic stenosis is a common heart disorder that affects nearly 5% of persons older than 75 years . many patients with severe aortic stenosis are not surgical candidates for surgical valve replacement owing to associated multiple medical problems and comorbidities . recently , transaortic valve implantation ( tavi ) showed a promise as an alternative option to conventional open heart surgery [ 3 - 8 ] . multislice detector computed tomography ( mdct ) is playing an increasingly important role in patient s screening protocol before tavi , provides detailed anatomic assessment of aortic valve morphology and calcification , aortic root measurement , aortic annulus size , comprehensive assessment of the aorta and suitability of iliofemoral access , and determines appropriate coaxial angles to optimize the valve implantation procedure [ 9 , 10 ] . mdct images are acquired through the chest , abdomen , and pelvis with a large imaging field of view , and potential incidental non - cardiac findings ( incfs ) can be detected . the prior unknown abnormalities that are identified on mdct without previous suspicion of disease and unrelated to the indications of the examination are referred to as incidental findings . the incfs may affect the patient s life expectancy following tavi and overall usefulness of the procedure . currently , there are limited published data with inconstant results on the prevalence of the incfs ; most published data are small patient s cohort with variable definition and classification of incfs . the goal of this study was to investigate the prevalence of incfs in pre - tavi protocol patients who underwent mdct as routine investigational workup before tavi procedure . sixty - seven consecutive patients with severe symptomatic aortic stenosis referred to our institution for pre - tavi assessment and were retrospectively evaluated between january 2010 and march 2015 . the local ethics committee approved the retrospective evaluation of mdct data of all patients . as a result of the retrospective nature of this study , waiver of informed consent mean age was 73  8 years , 35 ( 52% ) patients were male , and 32 ( 48% ) patients were female . patients with common contraindication to cta with intravenous contrast such as acute or chronic renal failure or prior contrast reaction were excluded . patients underwent retrospective ecg gated ct with 64 detectors ( hd 750 discovery ; general electrics , milwaukee , wi ) , and the ct parameters were as follows : collimation 64  0.625 mm , section acquisition 0.625 , tube voltage 120 kv , tube current based on body mass index , rotation time 330 ms , pitch 0.25 - 0.35 depending on heart rate , scan direction craniocaudal , and iterative reconstruction with 40% adaptive statistical iterative reconstruction ( asir ) . contrast materials injection protocol was total dose of material from 90 to 120 ml of iodixanol 320 ( ge , health care , princeton , nj ) . the injection rate was 5 ml / s followed by 50 ml of normal saline . ct images were reconstructed at slice thickness of 0.75 mm every 0.5 mm for coronaries , mediastinal and abdominal images were reconstructed at 2.0 mm thickness every 1 mm , and images analysis by multiplanar reformation was performed with dedicated software ( cardio q x - press , general electrics ) . images processing datasets included manually measured vessels diameters ( aortic root dimensions , aorta , iliac and common femoral arteries ) , the distance of the coronary ostia to the aortic annulus , and the presence and extent of calcification and touristy . incfs were diagnosed where an abnormality was found without previous clinical suspicion or known prior disease and were classified into three groups according to the anatomical location . the musculoskeletal groups encompassed the bone , joints , muscles and abdominal and chest wall as well as breasts . furthermore , on the basis of clinical relevance , non - cardiac findings were classified into three groups . group 1 findings were clinically significant and needed immediate attention and further evaluation ; group 2 findings were clinically significant and needed further follow - up by more imaging with other imaging modalities such as magnetic resonance imaging or ultrasound ; group 3 were incidental findings with no further follow - up or recommendations . sixty - seven consecutive patients with severe symptomatic aortic stenosis referred to our institution for pre - tavi assessment and were retrospectively evaluated between january 2010 and march 2015 . the local ethics committee approved the retrospective evaluation of mdct data of all patients . as a result of the retrospective nature of this study , waiver of informed consent mean age was 73  8 years , 35 ( 52% ) patients were male , and 32 ( 48% ) patients were female . patients with common contraindication to cta with intravenous contrast such as acute or chronic renal failure or prior contrast reaction were excluded . patients underwent retrospective ecg gated ct with 64 detectors ( hd 750 discovery ; general electrics , milwaukee , wi ) , and the ct parameters were as follows : collimation 64  0.625 mm , section acquisition 0.625 , tube voltage 120 kv , tube current based on body mass index , rotation time 330 ms , pitch 0.25 - 0.35 depending on heart rate , scan direction craniocaudal , and iterative reconstruction with 40% adaptive statistical iterative reconstruction ( asir ) . contrast materials injection protocol was total dose of material from 90 to 120 ml of iodixanol 320 ( ge , health care , princeton , nj ) . the injection rate was 5 ml / s followed by 50 ml of normal saline . ct images were reconstructed at slice thickness of 0.75 mm every 0.5 mm for coronaries , mediastinal and abdominal images were reconstructed at 2.0 mm thickness every 1 mm , and images analysis by multiplanar reformation was performed with dedicated software ( cardio q x - press , general electrics ) . images processing datasets included manually measured vessels diameters ( aortic root dimensions , aorta , iliac and common femoral arteries ) , the distance of the coronary ostia to the aortic annulus , and the presence and extent of calcification and touristy . incfs were diagnosed where an abnormality was found without previous clinical suspicion or known prior disease and were classified into three groups according to the anatomical location . the musculoskeletal groups encompassed the bone , joints , muscles and abdominal and chest wall as well as breasts . furthermore , on the basis of clinical relevance , non - cardiac findings were classified into three groups . group 1 findings were clinically significant and needed immediate attention and further evaluation ; group 2 findings were clinically significant and needed further follow - up by more imaging with other imaging modalities such as magnetic resonance imaging or ultrasound ; group 3 were incidental findings with no further follow - up or recommendations . the mean age of the included 67 patients was 73  8 years , and 35 male and 32 female ( table 1 ) showed patient characteristics . forty - six patients ( 69% ) had chest findings ( table 2 ) , 57 patients ( 85% ) had abdominal findings ( table 3 ) and 22 patients ( 33% ) had musculoskeletal findings ( table 4 ) . the total number of the incfs in the 67 patients was 248 , and number and percentage based on anatomical location were as follows : 95 ( 38% ) chest findings , 129 ( 52% ) abdominal and pelvic findings , and 24 ( 10% ) musculoskeletal findings . of these 248 findings , 23 ( 9% ) , 62 ( 25% ) , and 153 ( 66% ) findings belong to the first category , the second category , and the third category , respectively ( fig . 1 ) . number and distribution of 248 non - cardiovascular incidental findings in 67 patients by system and categories . three patients had significant , non - incidental , non - cardiovascular findings including gastric cancer , liver cirrhosis with partly ablated hepatoma and left hip prosthesis loosening , and one patient had malignant course of anomalous left coronary artery . distribution of incfs in category 1 ( findings that required treatment and immediate attention ) showed most patients ( 83% ) belong to chest findings , 13% belong to abdominal findings , and 4% belong to musculoskeletal findings . distribution of incfs in category 2 showed abdominal findings represent 58% , 12 patients ( 18% ) had liver findings that require further evaluation including solid lesions , one capsular retraction and one liver cirrhosis . twenty - six patients ( 39% ) had simple renal cysts belonging to category 3 , while only one patient had cyst with possible internal enhancement requiring further evaluation classified as category 2 . fifteen patients ( 22% ) had heterogeneous prostate enlargement with ( seven patients ) and without calcifications , chest findings ( 37% ) , and musculoskeletal ( 5% ) . twelve patients ( 18% ) had thyroid findings including thyroid enlargement ( three ) , nodules ( six ) and calcifications , and only 3% had musculoskeletal . distribution of incfs in category 3 showed chest findings represent 53% of the total chest incfs , abdominal findings represent 90% of total abdominal incfs , and musculoskeletal findings represent 20% of total musculoskeletal incfs . examples of category 3 incfs include : mosaic lung attenuation , diverticulosis , gallstones , right middle lobe / lingular sub - segmental atelectasis , simple renal cysts , fatty liver , and several small to borderline sized mediastinal lymph nodes . the main findings in this study are that all patients who underwent pre - tavi mdct workup had incfs . this study is one of few studies that report the prevalence and detailed nature of the non - cardiovascular findings in such specific population . this is the only study , to the best of our knowledge , that addresses the incidental findings based on anatomical location such as chest , abdominal and musculoskeletal findings . this system - based approach will be of great assist to interpreting physician to look for and report these findings more precisely in a systematic method . a more conservative approach in the classification of incidental findings was followed ; particularly in category 1 , there are findings that we think that need to be managed more promptly , such as anterior abdominal wall fat stranding and early abscess formation , and pulmonary edema and presence of lung infection , e.g. , tree in bud appearance and patchy ground glass opacity . early identification and prompt management of such abnormality may have a major impact in patients management and long - term outcome . the most common incf belongs to abdominal category ; a similar study showed that 99% of 200 patients had 456 of non - incfs , and most patients had multiple findings that fell into more than one group . incidental abdominal and pelvic findings contributed to 129 ( 52% ) of the total findings ( table 3 ) ; interestingly , few patients belong to category 1 , such as moderate to severe ascites , but majority of findings in category 2 that need further follow - up , and group 3 findings that incidental and further workup or recommendation was required . as per table 3 , there are multiple findings in category 2 including liver lesions , adrenal nodules , pancreatic and renal lesion , and presence of these incidental findings obviously , as per standard practice , initiates more workup . chest incfs compose 95 ( 38% ) of total findings , findings that need urgent management are more common than abdominal findings , and these findings include lung consolidation , atelectasis , pulmonary edema , pericardial effusion , and evidence of ongoing lung infection such as ground glass opacities and tree in bud . prompt identification and management of these incidental findings is of a great clinical value to prevent further clinical deterioration and to avoid short- and long - term complication . only lung nodules , hilar and mediastinal abnormalities , and thyroid nodules in category 2 need further follow - up ; on the other hand , there are multiple incidental chest findings that do not need any further workup ( table 2 ) . musculoskeletal findings are the smallest group , only 24 ( 10% ) , only one finding , anterior abdominal wall thickening , foci of air , and fat stranding that we thought it needs immediate attention . findings required follow - up such as vertebral collapse with possible cord compression and non - aggressive bone lesions . however , the majorities of msk findings are incidental and require no further workup such as non - complicated abdominal wall hernia , lipoma , mild scoliosis , and calcified nodes in the axillary and pelvic muscle ( table 4 ) . the first category findings are likely related to patient s severe aortic stenosis . this includes moderate amount of ascites in three patients , moderate to large amount pleural effusion in six patients , moderate to large amount pericardial effusion in three patients and pulmonary edema in three patients , and anterior abdominal wall infection in msk findings . the second category findings are more interesting as they might require further evaluation or correlation with additional radiological or non - radiological tests . lung nodule is a common incidental finding with the new generation chest ct examinations and has been reported in up to 51% of smokers aged 50 years or older . fleischner s society recommendations for follow - up and management of lung nodules smaller than 8 mm detected incidentally at non - screening ct in persons 35 years of age or older depend on the nodule size ( average of length and width ) and individual s risk factor of lung cancer like smoking . twelve patients ( 18% ) had thyroid findings including thyroid enlargement , nodules , and calcifications . incidental thyroid nodules ( itns ) are common . further evaluation of itn including neck ultrasound and possibly fna should take into consideration nodule size , imaging features and the patient s life expectancy , based primarily on age and comorbidities . only one patient had a cyst with possible internal enhancement requiring further evaluation classified as category bosniak two . incidental renal findings are common and mostly cystic in nature and classified as bosniak category 1 . twelve patients ( 18% ) had liver findings that require further evaluation including solid lesions , one capsular retraction and one liver cirrhosis . low ( age < 40 years ) and average ( age > 40 years ) risk individuals have no known 1ry malignancies with a propensity to metastasize to the liver , cirrhosis , or other hepatic risk factors . further evaluation is not required for such patients with sharply marginated solitary or multiple masses with low - attenuation ( 20 hu ) . lesion size , density features , stability as compared to prior if available , presence or absence of 1ry malignancy are important factors that lead to the proper management . presence of macroscopic fat with or without calcifications is diagnostic of benign adrenal myelolipoma . homogenous adrenal nodule with hu less than 10 in non - enhanced ct scan is most likely fat rich adenoma . however , tavi dedicated ct scans are aortic angiography which might interfere with this role . adrenal lesion of 1 - 4 cm size and benign features ( low density , homogeneous , smooth margins ) with no prior imaging or history of 1ry malignancy could be followed up after 1 year with ct or mri . the third category findings are more common , and typically these finding are incidental and require no further workup . for abdominal findings such as diverticulosis , gallstones , and fatty liver , common chest incidental findings such as granuloma scatter small cyst , and small pleural effusion and small calcified mediastinal lymph nodes , particularly have no major clinical relevance . lindsay et al in a recent study demonstrated that incidental findings in pre - tavi ct are common , and do not independently identify patients with poor outcomes after tavi procedure . detection of incidental findings on ct should not necessarily influence or delay the decision to perform tavi . in a total number of 260 patients incfs were observed in 204 patients ( 70.6% ) , eight ( 3.9% ) malignances were detected , and the authors concluded a high prevalence of non - cardiac findings on routine pre - tavi ct examination . in another study by gufler et al , in a total of 131 patients , 31% patients had significant non - cardiac findings , 19% chest and 12% abdominal findings . five lesions were considered potentially malignant , two renal cell carcinomas , one hepatoma , one mediastinal lymphoma , and one metastatic bladder cancer . the study found that prevalence of malignant incidental finding in pre - tav ct is 3.8% . however , this prevalence is not high in tavi patients with average age of 81.6 years compared to general population . a 2-year survival after tavi procedure was investigated by stachon et al , and the presence of potentially malignant findings ( pmf ) versus no pmf did not significantly influence decision or time to treatment . several findings which are highly suspicious for malignancy were less likely associated with invasive treatment ; the authors concluded that the frequently occurring radiological pmf did not influence 2-year survival after tavi procedure . this is a single - center study with relatively small number of patients , which might have some invalid representations of the population ; however , compared to other similar studies , our patients comparable to others , typical tavi patients are elderly with multiple associated commodities . one of the other important limitations is no follow - up of most of the patients , the real significance and impact of non - cardiac findings are unknown , but all our patients underwent successful tavi procedure and discharged home without any in - hospital complications , and most of the patients as per radiological findings will follow with their primary care physicians . incfs are common in routine pre - tavi ct presumably due to advanced age of patient population . these findings have variable clinical significance and some of them might require acute treatment while other might require additional evaluation and follow - up . most incfs do not influence the decision to perform tavi procedure , and do not affect post - procedure outcome . it is imperative to report pre - tavi ct ; beside cardiac and vascular findings , such incidental findings must be reported in a systemic method in a system - based approach to avoid missing important findings . this is a single - center study with relatively small number of patients , which might have some invalid representations of the population ; however , compared to other similar studies , our patients comparable to others , typical tavi patients are elderly with multiple associated commodities . one of the other important limitations is no follow - up of most of the patients , the real significance and impact of non - cardiac findings are unknown , but all our patients underwent successful tavi procedure and discharged home without any in - hospital complications , and most of the patients as per radiological findings will follow with their primary care physicians . incfs are common in routine pre - tavi ct presumably due to advanced age of patient population . these findings have variable clinical significance and some of them might require acute treatment while other might require additional evaluation and follow - up . most incfs do not influence the decision to perform tavi procedure , and do not affect post - procedure outcome . it is imperative to report pre - tavi ct ; beside cardiac and vascular findings , such incidental findings must be reported in a systemic method in a system - based approach to avoid missing important findings .
backgroundtranscatheter aortic valve implantation ( tavi ) is a new treatment option for patients with severe aortic stenosis . 
 pre - tavi procedure workup includes computed tomography angiography ( cta ) of the heart and aorta from aortic annulus to the iliofemoral arteries . 
 frequently , there are a number of incidental non - cardiac findings ( incfs ) in pre - tavi cta . however , the frequency and clinical significance of these incfs are unknown . 
 the aim of our study was to investigate the prevalence of incfs and their clinical significance.methodsthis was a retrospective review of 67 patients who underwent dedicated pre - tavi cta from 2010 till 2015 . 
 non - cardiovascular incfs were classified according to their clinical significance into three categories . 
 the first category includes findings that may require urgent treatment . 
 the second category includes findings that need further follow - up . 
 the third category includes incidental findings that require no further follow - up or recommendation.resultsthe total number of patients was 67 , and the mean age was 73  8 years . 
 all patients had incfs and the total number was 248 . 
 of the patients , 69% had chest findings , 85% had abdominal findings , and 33% had musculoskeletal findings . 
 results based on categorical classification were as follows : 9% , 25% , and 66% of these 248 findings belong to the first category , the second category , and the third category , respectively.conclusionnon-cardiovascular incfs are common in pre - tavi cta presumably due to increased age of such specific population . 
 these findings have variable clinical significance and some of them might require acute treatment or additional evaluation , and should be managed properly taking into consideration patient s life expectancy and comorbidities .