Severity of incidental findings stratified by location.

Table 5: Distribution of Category 1 - 4 incidental findings in the different body regions Body Abdomen/ Musculoskeletal/ Head Neck Thorax region Pelvis Extremities

Category [n] % [n] % [n] % [n] % [n] % 1 12 1.1 10 4.3 146 13.1 97 4.2 14 1.9 2 52 4.9 180 76.6 445 39.8 477 20.6 97 13.5 3 598 56.7 10 4.3 185 16.5 859 37.1 286 39.8 4 393 37.3 35 14.9 342 30.6 881 38.1 321 44.7 total IF 1,055 100 235 100 1,118 100 2,314 100 718 100

%)

Distribution of Category 1 and 2 incidental findings. Most Category 1 incidental findings were reported in the thorax (52.3%) and in the abdominal/pelvic region

(34.8%). Category 2 incidental findings were also mainly seen in the thorax (35.6%) and the abdomen/pelvis (38.1%).

Overall most frequent incidental findings. When disregarding severity, the most incidental findings were mucosal swelling/chronic sinusitis in 482 patients (Category

3), healed fractures in 249 patients (Category 4), renal in 248 patients

(Category 4), hepatic steatosis in 238 patients (Category 3), and hepatic cysts in 227 patients (Category 4).

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CATEGORY 1 FINDINGS

HEAD number incidental finding 4 suspicious or semimalignant lesion* 2 abscess, focal inflammatory lesion# 2 acute ischemia, suspected 1 hydrocephalus, disturbed CSF circulation 1 including edema* 1 osteolytic processes of cranial bone* 1 otitis media#

NECK number incidental finding 6 malignant or suspicious lesion* 3 thrombosis of internal/external jugular vein 1 vertebral artery dissection, suspected

CHEST number incidental finding 29 >= 1cm# 21 pneumonia/infiltration# 21 suspicious lesion* 18 metastasis* 18 pericardial effusion 6 pulmonary artery embolism 5 (lobar) atelectasis 5 malignant lesion (lung, breast, cardial)* 5 lung metastasis* 3 caverna, requires workup# 3 pulmonary edema 3 malignant pleural effusion* 3 pneumonia/atypical infiltration# 2 thrombosis of internal jugular vein, superior vena cava, subclavian vein 1 aortic lesion, requires workup 1 lymphangioleiomyomatosis 1 tuberculosis/miliary tuberculosis, suspected # 1 thrombus of cardiac ventricle/atrium

2

ABDOMEN/PELVIS number incidental finding 31 malignant or suspicious lesion, known malignancy* 16 metastasis, suspected* 8 chronic inflammatory bowel disease, suspected# 8 gastrointestinal tract inflammation# 7 urinary congestion ≥II° 7 suspicious lymph nodes* 3 diverticulitis# 3 invagination, suspected, volvulus 2 infection of the urinary tract, suspected# 2 infectious liver lesions# 1 aortic aneurysm, unstable 1 acute cholecystitis# 1 acute vascular occlusion 1 gastrointestinal bleeding 1 hydronephrosis 1 megacolon 1 hernial incarceration, suspected 1 gastric bleeding, suspected 1 subileus 1 venous thrombosis of pelvic axis, suspected

MUSCULOSKELETAL/EXTREMITIES number incidental finding 10 metastasis* 1 chordoma* 1 pathological fracture* 1 suspicious lesion* 1 acute occlusion of leg artery

* incidental findings classified as definite malignancy or lesions suspicious of malignancy # incidental findings classified as signs of inflammation

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CATEGORY 2 FINDINGS

HEAD number incidental finding 19 14 reduced brain volume, before age 50 8 stenosis, hemodynamically relevant, vessel occlusion 3 other 2 arteriovenous malformation 2 cholesteatoma, suspected 2 fracture, not or incompletely consolidated 1 cerebral aneurysm 1 multiple sclerosis

NECK number incidental finding 121 thyroid changes („lesion/s“, inhomogeneity, „nodule“) 56 struma nodosa 2 probably benign lesion 1 cerebral artery aneurysm 1 hemodynamically relevant stenosis

CHEST number incidental finding cardiomegaly, signs of myocardial insufficiency, 146 right heart overload 64 coronary sclerosis 50 pulmonary nodule(s) volume overload/congestion, including chronic 46 forms 39 aortic aneurysm 23 pulmonary artery 21 pleural effusion < 1 cm 10 mammary abnormalities 9 esophageal varices 8 myocardial scar, status post myocardial infarction 7 valve calcification 4 probably benign lesion 4 sarcoidosis 3 dilated cardiomyopathy 3 carnifying, consolidated pneumonia 3 other 2 aortic isthmus stenosis 2 emphysema before age 45 1 suspected pneumoconiosis

4

ABDOMEN/PELVIS number incidental finding 51 incidentaloma, most likely adrenal gland adenoma 45 hernia 37 hepatomegaly 35 liver cirrhosis 34 lesions, require workup, probably benign 33 splenomegaly 31 renal atrophy 24 intrahepatic cholestasis 21 urolithiasis 17 common hepatic duct ≥ 10 mm (no cholecystectomy) 14 aortic aneurysm 14 11 adrenal mass, requires workup 10 renal agenesis/unilateral shrinkage 9 aneurysm of hepatic, renal, gastroduodenal, common iliac artery 9 urinary congestion grade 1 9 portocaval collateral circulations 8 gallbladder hydrops 7 renal artery stenosis, suspected in one case 6 trabeculated bladder and bladder wall thickening 6 pancreatic duct ≥ 4 mm 6 papillary stenosis, suspected 6 stenosis, hemodynamically relevant, chronic arterial occlusion 4 focal nodular 4 gallbladder polyp 4 IPMN 4 portal vein thrombosis, with cavernous transformation, portal vein ectasia 3 liver adenoma 3 polycystic kidneys 3 other 2 chronic cholecystitis 2 nonacute aortic dissection 2 liver congestion, suspected 1 ≥ 4 cm 1 suspected jejunal AVM 1 colon polyp

5

MUSCULOSKELETAL/EXTREMITIES number incidental finding 41 osteopenia, suspected 14 pseudarthrosis 11 bechterew disease 11 , suspected 8 high-grade stenosis and chronic occlusion of leg artery 7 nonconsolidated fracture, untreated fracture 2 superficial femoral artery aneurysm 2 paget disease 1 sacroiliitis/rheumatic changes

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CATEGORY 3 FINDINGS

HEAD number incidental finding 482 circular, polypoid mucosal swelling, chronic sinusitis 74 mucosal swelling plus fluid level/secretion retention, acute sinusitis, rhinitis 37 atherosclerosis, hemodynamically irrelvant stenosis 3 other 2 sialolithiasis

NECK number incidental finding 7 atherosclerosis, hemodynamically irrelevant stenosis 1 laryngocele 1 esophageal diverticula, suspected 1 tracheal diverticula

CHEST number incidental finding 82 emphysema after age 45 33 aortic sclerosis, hemodynamically irrelevant vascular stenoses 18 pulmonary fibrosis 17 COPD signs, signs of chronic bronchitis 9 aortic ectasia 8 elonaged aorta/with kinking 7 large axial hernia 7 other 3 chronic/old venous occlusion 1 bronchial ectasia

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ABDOMEN/PELVIS number incidental finding 238 hepatic steatosis 147 atherosclerosis/aortic sclerosis/hemodynamically irrelevant stenoses 116 diverticulosis 83 ovarian 75 cholecystolithiasis, sludge, cholelithiasis 45 uterine myoma/inhomogenous uterus tissue 31 prostatic hyperplasia 27 elongated aorta/pelvic axis/kinking 16 chronic pancreatitis 15 accentuated pancreatic duct < 4 mm 14 duodenal diverticula, suspected 14 hydrocele 7 common hepatic duct < 10 mm (no cholecystectomy) 6 panniculitis/mesenteritis 6 other 5 malrotated kidneys 4 pancreatic pseudocyst 3 angiomyolipoma < 4 cm 3 inhomogenous/nodular prostate 2 aortic ectasia 1 giant cavernous of liver 1 thrombosis of hepatic vein branch

MUSCULOSKELETAL/EXTREMITIES number incidental finding 85 spondylolisthesis 71 spondylolysis 54 intervertebral disk protrusion/prolapse 52 scoliosis 8 spinal canal stenosis/neuroforminal stenosis due to degenerative changes 6 other 4 hip dysplasia/dysplastic femoral head 3 pseudospondylolisthesis 2 atherosclerosis, stenosis 1 extreme obesity

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CATEGORY 4 FINDINGS

HEAD number incidental finding 104 old ischemia and lacunae 77 reduced brain volume after age 50, hygroma(s) 56 leukoencephalopathy 34 arachnoidal cyst 28 healed fracture 25 frontal hyperostosis 24 calcified basal ganglia 12 increase in lymph node size and number, not suspicious 10 osteoma 9 other 8 subcortical atherosclerotic encephalopathy 5 atheroma, lipoma, fibroma 1 bone hemangioma

NECK number incidental finding 32 increase in lymph node size and number, calcification, not suspicious 2 thyroid cyst 1 other

CHEST number incidental finding 138 increase in lymph node size and number, calcification, not suspicious 48 residual thymus 29 granuloma 28 small paraesophageal axial hernia 23 pulmonary scarring 15 gynecomastia 12 pleural plaques, scarry changes 3 fibroma, lipoma 3 pericardial cyst 3 other 2 calcareous 1 breast changes, definitely benign

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ABDOMEN/PELVIS number incidental finding 248 renal cyst(s) 227 hepatic cyst(s) 137 lymph nodes increased in number and size and calcified, not suspicious 78 liver hemangioma 43 focal hepatic steatosis 29 prostate calcification 23 pancreatic atrophy, pancreatic lipomatosis 22 splenic cyst 12 splenic hemangioma 11 renal infarction 11 complex renal cysts 8 postinflammatory/postspecific changes of the spleen, e.g., calcification 7 abdominal separation 5 splenic infarction 5 pancreatic cyst 5 other 4 postinflammatory changes of the liver 3 horseshoe kidney 3 nabothian cysts/cervical cyst

MUSCULOSKELETAL/EXTREMITIES number incidental finding 249 healed fracture 33 vertebral hemangioma 14 bone cyst 14 lipoma 8 osteoma 3 other

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