Microsoft PowerPoint - MDCT.ppt

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1 MDCT of the chest: Pulmonary embolism and acute aortic disease 劉原彰醫師影像診療科部急重症影像診療科長庚紀念醫院林口總院

2 大綱 MDCT 在急診胸痛病人扮演角色 MDCT : imaging of pulmonary embolism MDCT: imaging of aortic dissection MDCT: imaging of the heart non-ecg gated CT imaging ECG-gated cardiac CTA Update from 64-slice CT to 320-slice CTA

3 至少一半以上急診胸痛病患是沒有心臟方面疾病 Triple rule-out CT 可以快速找出病因. Chest pain: Stable angina Pulmonary embolism (PE) Aortic dissection. Acute coronary syndrom transmural myocardial infarction (MI) subendocardial MI unstable angina

4 Acute aortic dissection tearing aortic pain with immediate onset, unequal extremity pulses or blood pressures, and mediastinal widening on chest radiograph. 4% 7% of patients with aortic dissection may have none of these findings CT identified 99% acute aortic disorders, including dissection, intramural hematoma, penetrating aortic ulcer, new or enlarging aneurysm, or acute aortic rupture. Radiology. 2006;238:

6 Pulmonary embolism Clinical scoring systems such as the Wells and Geneva scores can be used to risk stratify patients suspected of having PE, but they are insufficient to exclude the diagnosis alone. Diagnostic imaging strategies include ventilationperfusion scanning, lower extremity sonography, CT pulmonary angiography (CTPA), and conventional pulmonary angiography (CPA). Among these methods, CTPA has become the first line tool for evaluation of PE in the acute setting.

7 4-slice CTPA with CPA in 93 patients, the sensitivity and specificity of CTPA were 100% and 89%, respectively. Radiology. 2004;233:

9 Acute coronary syndrome ACS encompasses a spectrum of presentations ranging from unstable angina to acute MI. 診斷 ACS: clinical history, electrocardiogram (ECG), and cardiac enzymes. 大多數胸痛病患 normal ECG and cardiac enzymes. 主要都在觀察病情變化, 僅 15% 是真正 ACS. 2~5% 真的 ACS 沒診斷出來因此需要更快速而且精準的檢查

10 第一類很明顯是 ACS. The ECG is abnormal The cardiac biomarkers are elevated, clinical history high risk for coronary artery disease. This group of patients is typically sent directly to the cardiac catheterization laboratory.

11 第二類 have minimal risk for coronary artery disease and a reasonable explanation for the chest pain 例如 : musculoskeletal injury 這類病患可以 discharged home without further work-up.

12 第三類佔 50% 左右 equivocal findings on the chest pain work-up. 一開始的時候 The history may be atypical, the ECG nonspecific or normal, the cardiac biomarkers may be normal, In this large group of patients, noninvasive imaging may be useful for clarifying the diagnosis.

13 影像檢查 Radionuclide myocardial perfusion imaging high negative predictive value (99%) for ACS. 通常僅在正常時間內服務對其他胸痛原因無法釐清 echocardiography. 急診 available sensitivity for ACS is good (90%) specificity is comparatively poor (53% for MI, 78% for ischemia). 主要看 wall motion abnormality, 無法區分新舊 Magnetic resonance imaging (MRI) multidetector cardiac CT.

14 Radionuclide myocardial perfusion imaging echocardiography. Magnetic resonance imaging (MRI) ability to evaluate myocardial perfusion, function, and viability. contrastenhanced, resting cardiac MRI had a sensitivity of 84% and a specificity of 85% for the diagnosis of ACS. 缺點 : 轉運, 檢查時間長, and the incompatibility of MRI with pacemakers, implantable cardioverterdefibrillators, and other metallic devices. Multidetector cardiac CT.

15 Multidetector cardiac CT coronary artery disease, aortic dissection, and PE. 也可以同時診斷 : pneumonia, pneumothorax, esophageal rupture, tumor.

16 顯影劑濃度與時間關係 Hu time

18 Triple rule-out CT 的挑戰輻射劑量顯影劑施打的注射量 ( 腎功能 ) 掃描時間點閉氣時間較長影像解析度心律變化, 心跳速率控制. ======================================== 320-slice CT 有可能可以解決上述問題照相技術師 + 護士 + 判讀醫師必須能夠 24Hr available

21 Conclusion Diagnostic accuracy for the detection of acute aortic dissection and PE are equivalent or superior to competing methods. For ACS, CT coronary angiography has an excellent negative predictive value. Given the prevalence of chest pain and the considerable radiation dose from CT, clinical tools that can reliably exclude life-threatening causes of chest pain should be rigorously applied to avoid unnecessary imaging.

22 Websites to subscribe to

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2011.07.05 1 2 3 2008/06/14 99 ~ 100 4 2008/06/14 300 91 93 2495 2219 578 1000 3 5 2011-03-24 43% 57% 208 6 99 ~ 100-1 99 ~ 100-2 7 - http://www.youtube.com/watch?v=bnsi4icp8oo - http://www.youtube.com/watch?v=ibbxfolqnyu