Justification of the use of CT for individual health assessment of asymptomatic people: the Chinese experience

Transcription

1 Justification of the use of CT for individual health assessment of asymptomatic people: the Chinese experience Liang Wang, MD, PhD Professor, attending radiologist Dept. of Radiology Tongji Hospital, Huazhong University of Science & Technology, Wuhan, CHINA

2 Background Knowing asymptomatic is important: a condition that it fails to show noticeable symptoms may develop symptoms later and require watch and wait or early treatment, e.g. cancer may resolve itself or become benign Be alert to possible problems unknowingly spread the infection to others Precautionary steps must be taken Excerpt from Wikipedia

3 Background Certain CT procedures for IHA of asymptomatic people are justified in certain circumstances in some countries The proportion of CT exams as source of radiation is increasing Technologic advance is profoundly changing our understanding of the use of CT for IHA of asymptomatic people

4 Objectives to summarize and analyze the utilization of CT for IHA of Keypoints: Feasibility and necessity of CT for IHA of asymptomatic people in China Rational use of CT for IHA of asymptomatic people in China Current application status of CT for IHA of asymptomatic people in China

5 1.Feasibility and necessity of CT for IHA of Chinese data: Usage of CT has increased dramatically over the last two decades in Chinese hospitals More than10,000 CT scanners in Chinese hospitals Rural community hospitals may have one or more CT scanners CT scanners per million Chinese population is 8.6

6 State-of-the-art imaging modalities in one Top 10 Hospital in China

7 Tongji University Hospital Chinese data: a hospital s medical statistics 2010: Out-patients: 2.90 million In-patients: 86,000 Operations: 42, 000

8 Feasibility and necessity of CT for IHA of Certain CT procedures for IHA of asymptomatic people are justified inchina The price of a CT exam is cheap in China, e.g per plain CT head exam Among medical diagnostic modalities, CT contributes the most man-made radiation in China Technology advances are profoundly reducing CT dose, e.g. coronary CT angiography

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10 2.Rational use of CT for IHA of Chest :Coronary CT angiography (CTA) Patients with myocardial infarction or sudden cardiac death may be asymptomatic in China CTA is used as an IHA tool for detecting coronary artery disease of asymptomatic people in China, e.g. low dose CTA was used to evaluate coronary stenosis, and characteristics of a plaque, especially vulnerable plaque, in asymptomatic people

11 Chest : Coronal CTA Li, et al published a CTA IHA study in 584 asymptomatic people to assess the prevalence of noncalcified coronary plaques 38.4% had non-calcified plaques Conclusions: Hypercholesterolemia and diabetes mellitus are high risk factors for the prevalence of noncalcified plaques for asymptomatic people Academic Radiology, Vol 19, No 5, May 2012

12 Chest : Coronal CTA Li, et al published a CTA IHA study in 584 asymptomatic people to assess the prevalence of noncalcified coronary plaques 38.4% had non-calcified plaques Conclusions: Hypercholesterolemia and diabetes mellitus are high risk factors for the prevalence of noncalcified plaques for asymptomatic people Academic Radiology, Vol 19, No 5, May 2012

13 Chest: Coronal CTA Dual source CT (DSCT) with adaptive sequence is currently considered to be the most effective tool to reduce radiation dose of CTA in China Xu, et al, published a DSCT IHA study to evaluate coronary artery stenosis in early diabetes or prediabetes asymptomatic myocardial ischemia. Diabetes Care 2013;36(6):

14 Chest: Coronal CTA Lv, et al. demonstrated volume CT dose index (CTDIvol) produced by prospective ECG gating CTA was about a quarter of the value with retrospective ECG gating CTA in their study

15 Indications for Coronal CTA as an IHA tool for men elderly over the age of 40 family history of premature coronary heart disease, smoking (current smoking > 10 cigarettes / day) high blood pressure high cholesterol severe obesity (overweight> 30%) history of cerebral vascular or peripheral vascular occlusion

16 Chest :lung Most IHAs focus on the detection of early-stage lung cancer and lung damage of asymptomatic smokes with CT in China

17 Chest :lung Wang, et al.published a low dose CT IHA study in the population > 40 years old.in 500 cases, there were 6 cases of lung cancer tube voltage kV tube current 10-30mA for 50 kg body weight, 20-30mA for 60 kg body weight, 30mA for > 80 kg body weight image quality could meet diagnostic requirements, radiation dose has decreased by 75-90%

18 Chest :lung Li, et al. published an IHA study of low-dose lung HRCT (tube voltage 120kV, tube current 40 mas) to investigate the lung damage of asymptomatic smokers and non-smokers found that the incidence of lung emphysema, air trapping and pulmonary parenchyma micronodule were significantly increased in smokers than non-smokers

19 Chinese guidelines on lung cancer IHA with low dose CT Age of 40 years or above high-risk groups: smokers and passive smokers, family history of cancer occupational dust or radiation exposure history regular contact with cooking oil fumes (COF)

20 Head Head CT is used as an IHA tool for detecting intracranial lesions, skull lesions and other head diseases of

21 Head Wang, et al published a head CT IHA study of 21,358 asymptomatic people demonstrated asymptomatic cerebral infarction (ACI) prevalence was 3.84%, followed by sinusitis, encephalomalacia, intracranial tumors and skull bone tumors ACI is low before the age of 40 ACI rise after the age of 40 years old

22 asymptomatic people in China Head Ding, et al, published a head study with low dose CTA (tube voltage 80kV, tube current 150 mas) to investigate intracranial aneurysms (ICA) Effective radiation dose was reduced by 69.73% no significant differences in sensitivity, specificity and accuracy for the detection of ICAs

23 Indications for low-dose head CT as a IHA tool for years old with high blood pressure Diabetes Smoking over 50 years old routine annual low-dose CT IHA for head diseases Alcoholism family history of stroke and less than 40 years old intracranial arterial not recommended for stenosis routine CT to avoid ionizing radiation

24 Head: Nasopharynx Globally, 80% of patients with nasopharyngeal carcinoma (NPC) are in China Early NPCs are mostly asymptomatic but can be detected by IHA with CT

25 Head: Nasopharynx Chen, et al, published a study with low dose skull base CT ( a decrease in tube current from 200 mas to 70 mas) ocular radiation was reduced (from mGy to mgy) image quality is not significantly sacrificed

26 Indications for low-dose CT as a NPC IHA tool for Liver in the southern provinces of China Aged 30 to 59 years Family history of NPC regular contact with cooking oil fumes (COF), carcinogenic chemicals Tobacco and alcohol use

27 asymptomatic people in China Abdomen and pelvis Early neoplasms of abdomen and pelvic, such as HCCs, are mostly asymptomatic but can be detected by IHA with CT High tube current is usually used in routine abdominal and pelvic CT to obtain high image quality, which leads to a high radiation dose to the patient Simply reducing tube current leads to an increase in image noise

28 asymptomatic people in China Abdomen and pelvis:liver Xu, et al, used idose enhanced CT iterative reconstruction technique to obtain high-quality images at lower dose levels effective dose (ED) was reduced by 49.71%

29 Indications for low-dose liver CT as an IHA tool for HCC Risk Factors & High Risk Populations Hepatitis B Infection Hepatitis C Infection Alcohol Aflatoxin B1 Drugs, medications, chemicals, such as vinyl chloride Hemochromatosis Cirrhosis

30 Abdomen and pelvis:pancrease Hu, et al, published a pancrease study with low dose GE lightspeed VCT (abdominal circumference/current: < 90cm/60-80mA; cm/70-90mA; 110cm/90-100mA) to obtain high-quality imaging at lower radiation dose

31 Abdomen and pelvis:kidney Mu, et al, published a RCC IHA with CT (tube voltage 120kV, tube current 100 mas) obtained satisfactory perfusion images effective radiation dose was 8.95mSv

32 Indications for low-dose kidney CT as an IHA tool for RCC Risk Factors & High Risk Populations Over 40 years old Smoking Obesity At other professional such as oil, leather, asbestos, other industries Family history of RCC

33 Abdomen and pelvis:kidney Zhu, et al, published a urinary calculi study with low dose CT (tube voltage 120kV, tube current 50 mas) obtained high quality images to detect urinary stone

34 Abdomen and pelvis:bladder Chen, et al, published a study with low dose bladder CT (tube voltage 120kV, tube current 40 mas) after inflating bladder obtained satisfactory images to detect urinary lesions

35 Indications for low-dose CT as bladder cancer IHA tool for Bladder Cancer Risk Factors & High Risk Populations: family history of bladder cancer smokers contact with carcinogenic chemicals

36 Abdomen and pelvis:colorectum Chen, et al, published a colorectal cancer IHA study with low dose CT (tube current 50 mas) after inflating colorectum obtained satisfactory images sensitivity, specificity, and accuracy were 96.5%, 62.5%, 89.2%, respectively

37 Indications for low-dose CT as a colorectal cancer IHA for positive immunoassay fecal occult blood test first-degree relatives with colorectal cancer history of cancer history of intestinal polyps have both or more of the following: chronic diarrhea chronic constipation bloody stool mucus containing stool psychiatric injury history of chronic appendicitis

38 Bone Feng, et al, published a lumbar disc herniation (LDH)IHA with CT in asymptomatic air force fighter jet pilots LDH accounted for 27%

39 Bone Zheng, et al, used iterative reconstruction technique in 256-slice lumbar spine CT to obtain high-quality imaging at lower radiation dose

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41 3.Current application status of CT for IHA of Certain CT procedures for IHA of asymptomatic people are justified inchina CT for IHA of asymptomatic people is being performed in China CT examinations for IHA of asymptomatic people mainly reimbursed by employers in China Multidisciplinary research efforts is profoundly changing our understanding of the use of CT for IHA of

42 THANK YOU Liang Wang, 王良,MD, PhD full professor, attending radiologist