Aquifer - Radiology Actual Exam Questions With Answers

Aquifer - Radiology Actual Exam Questions With Answers Window vs. Reconstruction on CT? - ANSWER- Reconstructions - processing of the raw CT data allows for better resolution of the structures [higher resolution and higher contrast] Reconstruction can be done in 3D (ortho) or in a linear way too (vascular) What is the total range of hounsfield units availabe? - ANSWER- -1000 (air) to +1000 (metal) [so range is 2000] What does a typical computer display show for greyscale range? What can the human eye actually distinguish? - ANSWER- 256shades (that means each shade of grey covers ~8HU) The can only distinguish 17 shades of grey What is a good way to check diaphragm flattening? - ANSWER- Look at the lateral film Diaphragm will be flat like you can set a ruler down on the edge What can a poor inspiration/hypoinflation appear like? - ANSWER- consolidation or PNA How to look at the lung fields? - ANSWER- Sweep or a zig zag down the lung field (both in PA and lateral views) look for focal, diffuse, BL asymmetrical, interstital/vasc markings, lucencies (cavity/bullae/PTX), compare upper and lower and L/R zones Middle lower zones Which hilum should always appear higher on the radiograph? - ANSWER- The LEFT sided hilum should be higher - if its not its pathological What to look for with the heart? - ANSWER- Size of the heart - the cadiac:thoracic cavity ratio LA LV What mediastinal lines should be observed on PA film? - ANSWER- R paratracheal line Azygous area Azygoesophageal line Paraaortic line (all the way down) If you can see these you need to figure out the reason why How to look at the bones on Xray? - ANSWER- Quadrant method [above and below the ribs] (the middle lung section you just also go down the spine looking for abnormalities, mets, or collapse When should you START looking at OLD films? - ANSWER- AFTER you have COMPLETELY evaluated the new scan What are the ACR appropriateness criteria? - ANSWER- The aim is to provide continuously updated evidence-based algorithms that ensure the safest, most costeffective, and most efficient path to radiological diagnosis or intervention matched to specific variants of clinical presentations. Federal LAW requires referring physicians to consult Appropriate Use Criteria (AUC), such as ACR Appropriateness Criteria, prior to ordering advanced imaging services (ADIS), including CT, MR, nuclear medicine, and PET, for Medicare patients. How are appropriateness criteria divided/staged? - ANSWER- Older appropriateness rating tables used a numerical rating scale: • Usually Appropriate = 9, 8, or 7 • May be Appropriate = 6, 5, or 4 • Usually Not Appropriate = 3, 2, or 1 Newer appropriateness rating tables simply use the three categories: • Usually Appropriate (Green cells in the table) • May be Appropriate (Yellow cells in the table) • Usually Not Appropriate (Red cells in the table) What lobe of lung is seen at the apicies? - ANSWER- The R and L upper lobes What is the silhouette sign? - ANSWER- The visual interface between structures of different density. Its actually when a silhouette is LOST that we say its a "silhouette sign" What is spine sign? - ANSWER- When the combined density of the vertebrae and some source of fluid/consolidation make the vertebrae look MORE dense [just like ice over water accentuates the ice appearing like they have increased density even though they still the same ice] What are cases in which spine sign occur? - ANSWER- Spine sign - vertebral bodies should be relative lucent (black) above the diaphragm on lateral projection. -Lateral x-ray goes through spine + pneumonia and vertebra will appear whiter (fewer xrays reach detector since some are absorbed in the pneumonia) - Helpful sign for detection of lower lobe pneumonia. - - Very useful for detecting LLL pneumonia behind the heart. - If vertebral bodies appear more dense (whiter) above the level of diaphragm, and part of one of the diaphragms is obscured → spine sign → sign of lower lobe pneumonia - There are other causes for the spine to appear whiter (such as a blastic bone metastasis). What is the lingula aligned with? - ANSWER- The left heart border (this is more visible in the lateral view xray) What are air bronchograms? - ANSWER- Air-filled bronchi within an area of consolidation. These are frequently seen in pneumonia, but can also be seen in some tumors and other lung abnormalities More common in alveolar disease Air bronchogram ≠ pneumonia Can be seen in lung cancer (adenocarcinoma with bronchioloalveolar pattern) Can be seen in lymphoma of the lung Seen in: A. Pneumonia C. Pulmonary edema D. Pulmonary hemorrhage E. ARDS Which patients w/ PNA should have a follow up xray? - ANSWER- All patients > 40 years History of recurrent pneumonia Current/former smokers Patients whose symptoms do not resolve What is the MC cause of solitary pulmonary nodules on CT scan? - ANSWER- Welldifferentiated adenocarcinoma (formerly known as bronchioalveolar carcinoma (BAC)) Common in smokers AND non-smokers (esp females) True/False - mycoplasma PNA can cause Kerley B lines as seen in CHF? What are Kerley B lines? - ANSWER- TRUE Kerley B lines (septal lines) represent thickening of interlobular SEPTA Note that sometimes Kerley B lines can be distinguished because they extend and touch the pleura What are ground glass opacities? - ANSWER- "Ground glass" is a radiology descriptive term (used in both chest radiographs and CT imaging) to indicate that blood vessels are not obscured, as would be the case in alveolar lung opacities. Compare ground glass opacities vs. consolidation opacities - ANSWER- Ground Glass: Blood vessels are not obscured on CT. "Smoke-like" opacity on CT that does not obscure blood vessels Descriptive term (usually primarily used on CT imaging). May represent either interstitial or alveolar disease. Some diseases (like PJP infection in HIV infection, early edema, etc.), often have "ground glass" opacities early in the disease process. Consolidation: BLOOD VESSELS are obscured on CT and air bronchograms are more common. What dosage of radiation in x-rays is 1 CT scan worth? - ANSWER- 150 x-rays worth of radiation per CT scan (ON AVERAGE) Some scans use more or less however depending on the application - for example PE scan = 400CXRs Abdominal Scan = 750CXRs V/Q scan = 800CXR