CORE Case 1 Workshop

1. Petra Lewis MD Professor of Radiology and OBGYN Geisel School of Medicine at Dartmouth CORE Case 1 Workshop

2. Learning objectives • Understand the meaning of the silhouette and sign signs • Understand how these concepts can be applied in the diagnosis and localization of pneumonias • See how viral pneumonias differ in appearance • Describe how pleural effusions appear on chest radiographs on different views • Understand how the appearance of effusions varies in empyema and hydropneumothorax • Understand the factors affecting the risks of medical radiation and how they can be reduced. • Calculate the risks to a real patient from his medical radiation exposure during a single clinical episode

3. What questions/difficulties did you have arising from the case

4. Pneumonias

5. Silhouette sign

9. RLL pneumonia

21. Pleural effusions

22. Pleural Effusions • How much fluid do you need to see on • A PA CXR? • A lat CXR? • A supine CXR? • A CT scan? • How else can you visualize pleural fluid? • Characteristics of fluid vs consolidation?

23. Small effusions

24. Small effusions

25. Decubitus views

28. Supine pleural effusions

34. Radiation Risk

35. Radiation risk • What factors affect how much risk patients are at from medical radiation?

36. Relative risks of exams

37. Radiation Equivalents Average background = 3mSv Metter et al. 2008, 248, 254-263.

38. Case study HT abdominal CT27 year old with complicated pancreatitis

40. HT Radiology Studies 12/7/06-2/6/07

41. What is his increased risk of dying of a malignancy due to his radiation exposure during this hospital stay?

42. How much radiation did HT receive?

43. So our patient received an estimated dose of ? mSv

44. Cancer induction rates • 8% fatal cancers per Sv (1000 mSv) • = % fatal cancers risk for HT • Fractionation reduces risk by 50% • = % fatal cancers risk for HT • Younger patient (<40) doubles risk • (much higher for young children) • = % fatal cancers risk for HT

45. Cancer induction rates • Lifetime risk of fatal cancer • 24% males, 20% females • = /24 x 100% increased risk of dying of a cancer from his hospital exposure • = • Note – his risk of developing any type of cancer is about twice this (fatal and non-fatal)

46. How can we reduce risk?

47. Appendix

48. Learning Objectives from CORE 1 • Review CXR anatomy including the location of the lobes of the lung and their relationship to fissures • Be introduced to the American College of Radiology (ACR) appropriateness criteria for imaging • Learn the indications for chest imaging in patients presenting with upper respiratory tract infection symptoms. • Learn the radiographic presentations of typical alveolar pneumonias in different lobes of the lung. • Understand the concepts of “silhouette sign” and “spine sign” and how they can be used to localize abnormalities on chest radiographs. • Understand the term “air bronchograms” and the significance of this sign. • Learn how some tumors can appear similar on imaging to pneumonia. • Be introduced to the typical radiographic appearance of PCP pneumonia, and other opportunistic and atypical pneumonias and how they differ radiographically from typical bacterial and lobar pneumonias • Understand the meaning and appearance of “ground glass” opacities on chest radiographs and CT scans. • Understand the use and limitations of portable radiographs in the ICU. • Learn the imaging features of ARDS • Acquire a basic understanding of patient radiation doses from common examinations and how we can try to limit them. • Learn the common imaging features of various types of pleural effusion including simple, hydropneumothorax, empyema and loculated pleural fluid collections (“pseudotumors”). • Understand how pleural fluid appears differently on erect and supine radiographs. • Learn when image guidance can help in the drainage of pleural fluid.