Radiology Notes Monday, August 19, 2013 2:37 PM http://fitsweb.uchc.edu/student/radiology http://www.med-ed.virginia.edu/courses/rad/index.html http://www.radiologyassistant.nl/en/p497b2a265d96d/chest-x-ray-basic-interpretation.html#in514d80fcb1408 http://www.stritch.luc.edu/lumen/MedEd/Radio/curriculum/Medicine/Pleural_effusion1.htm TEST  2 hours - 80 questions  Management, next step, cases with images, just an image  Images repeated on exam that we saw in class

Introduction to Radiology/Imaging

Plain Film  Plain x-ray is a 2D representation of a 3D object. Only when you see the object in two planes can you see what something is and define it’s true shape  X-rays have 5 tissues you can identify based on absorption coefficient; need difference in absorption coefficient of 5% o Air (black): photo does right through and doesn’t get absorbed; -1000 o Water, muscle, blood, soft tissue (gray) o Fat (dark gray) o Bone (white): calcium o Metal (white); +1000  Brightness on x-ray: lead > barium > bone > muscle/blood > liver > fat > air  Normal chorinal angle is about 70 degrees. There are subchorinal LNs which can elevate the main stem bronchus  PA vs. AP – always labeled by direction of path of beam (supine is AP, anterior to posterior) o routine lateral is called left lateral, beam goes from right to left  Collimator – lead square used to limit boundaries of x-ray beams; triangulation: use images with history and physical  Too much light = over exposed, so looks black; not enough light = underexposed (energy can’t quite penetrate)

MRI  Non-ionizing radiation, Great for looking at soft tissues  Contraindication with pacemakers/ferromagnetic devices  T1 - fluid is black  T2- fluid is white

Fluoroscopy  Continuous stream of x-ray to watch what’s going on in real time; can watch motion  Downside is higher dose of radiation  Can use with contrast agents o Inulin gets picked up by the kidney; Intravenous Pyelogram = inulin tagged with iodine CT  X-ray in thin slices; very sensitive; each line = ray; 1000 slices of 1mm cuts  Each slice has three dimensions  Orient yourself look at patient’s feet, upward

Nuclear Imaging  Outgrowth of Manhattan project (development of first atomic bomb)  Radiation with alpha/beta/gamma  PET (Positron Emission tomography) scan: tag positron with glucose and look for metabolically active tumors o Hope is to one day tag it so it can destroy these areas

Ultrasound  High frequency sound waves in water (know speed of sound in water)  No ionizing radiation, relatively inexpensive, real time evaluation, can utilize color Doppler to look at flow  Applications: liver, gallbladder, biliary system, kidney; terrible with bowel

Radiation Dangers and Protection  Unit of energy in x-ray is called a Rad o Difference in absorption in different types of tissue  Sievert is the amount of radiation a particular unit of tissue receives  For the average CT of chest or abdomen, dose is 10-15 milliSieverts (CXR is .01 mSv) o CTA is 15-20 milliSieverts o Average CXR is 0.01 milliSieverts o 10milliSieverts = 1/1000 risk of developing cancer o Abdominal CT scan: 1/143 risk o Normal radiation from natural sources – normally 1-3 mSv/year . In areas of high background, 3-13 mSv/year o Over 50 mSv at one time is high risk for developing cancer  Radiation injury: When you get a photon of energy that comes through the tissue at the right amount, it knocks out one of the outer electrons and creates and ion (in water, activates hydroxyl ion). This can potentially cause damage to your DNA. Photon can actually damage the DNA or break the strand if it hits it directly.

Rotations Page 1 hydroxyl ion). This can potentially cause damage to your DNA. Photon can actually damage the DNA or break the strand if it hits it directly.  Optimization of protection by keeping exposure as low as reasonably achievable; dose limits for occupational people  Medical, occupational, and public exposures all exist

CHEST  40% of all imaging done in US are CXR  Adequate film: o CXR ideally done in PA position, which is better for heart size (10-20% overestimation when do an AP). Done at 72 inches at maximal inspiration . Normal heart should be less than 50% of cardiothoracic ratio o Adequate inspiration: 9 posterior ribs on R side; if see 11-12 ribs, likely COPD . 2nd anterior rib follow-up, corresponds to 2nd posterior rib o Non rotation: clavicles should be equidistant from clavicles . If spinous process closer to left clavicle, then rotated left anterior oblique o Degree of penetration: . densitometer, vertebral bodies through the density of heart, pulm vascularity to LLL through heart o Routinely take left lateral (want heart on left side of chest closest to the film)  Systematic Approach o Bony framework . Bony structures: cervical spine, clavicles, AC joint and acromion, scapula, glenoid, coracoid process, humeral head, ribs, vertebrae, pedicl es (will often see metastatic disease here) o Soft tissues . Soft tissue: calcification of carotid, LN calcification, masses, abdomen, stomach bubble, splenic flexure, neck and chest wall o Lung fields and hila (see his tutorial) . Right upper, middle and lower lobes; left upper and lower lobes . Left  The right lung comprises 10 segments: 3 in the right upper lobe (apical, anterior and medial), 2 in the right middle lobe (me dial and lateral), and 5 in the right lower lobe (superior, medial, anterior, lateral, and posterior).  1 fissure- oblique . Right  The left lung comprises 8 segments: 4 in the left upper lobe (apicoposterior, anterior, superior lingula, and inferior lingul a) and 4 in the left lower lobe (superior, anteromedial, lateral, and posterior).  2 fissures . TB likes posterior segment of upper lobe . Immunocompromised- superior segment of lower lobe o Diaphragm and pleural spaces . Right hemidiaphragm is higher than the left – if left higher may have loss of lung volume (e.g. atelectasis) o Mediastinum and heart o Abdomen and neck o Pit falls . Poor inspiration . Over or under penetration . Rotation  Lungs o Upper, middle, lower lung field; hilar structures including PA and PV; pulmonary vascularity, diaphragm, costophrenic sulcus; right hemidiaphragm is usually higher than left (if left higher, might be phrenic nerve palsy but most commonly loss of lung volume such as atelectasis; tumor). Then compar e one side to the other o Carina . Look for lymph nodes in this area (e.g. stage 4 lung cancer, no longer operable) Silhouette/Structure Contact with Lung

Upper right heart border/ascending Anterior segment of RUL aorta Right heart border RML (medial) Upper left heart border Anterior segment of LUL Left heart border Lingula (anterior) Aortic knob Apical portion of LUL (posterior) Anterior hemidiaphragms Lower lobes (anterior) (right anterior oblique = left posterior oblique)

Medial segment of middle lob abuts the heart

Rotations Page 2 Rotations Page 3  Heart o Cardiac shadow/size. Borders of heart, trachea and bifurcation, atria/ventricles o Right atrial enlargement . Could be tricuspid regurgitation . Right sided strain  Lateral view o Square vertebrae, aorta and scapula look a bit different. Lungs should be blacker as you go down in a lateral view. o On lateral, to know which diaphragm you’re looking, gastric bubble on left. Left hemidiaphragm has heart on it  Silhouette sign – two tissues of similar densities that are next to each other, you won’t be able to recognize the difference o Vertebra should get progressively darker as you go down

 Look at segments : o right upper lobe segments – superior, anterior, posterior (posterior associated with TB); left upper lobe segments – anterior, apical posterior; right lower lobe – superior, anterior, posterior, mediolateral  Pathology / other o Tracheal deviation: thyroid, thymus, teratoma, etc. o Most common cause of perforated viscous is an ulcer (duodenal or gastric). Anytime you suspect a perforation or a leak from an anastomosis etc ----can ONLY use water soluble contrast!!! . Other causes- diverticulitis (unusual), iatrogenic, colon (intraperitoenum – cecum, transverse, sigmoid, jejunum) . If patient cannot stand, do Left Lateral Decubitus  Do left side down so that air goes up to right side and see air above liver

Rotations Page 4  Do left side down so that air goes up to right side and see air above liver o Hiatal hernia – can see it hyper dense behind the heart. On lateral, see air pocket o May occasionally have cervical (rudimentary) ribs, air in subcutaneous tissue, absence of clavicles etc. Can use a grid to c lean up scatter.

 Consolidation and atelectasis (collapsed alveoli – can be due to obstructive (plugging), compression (fluid collection), scarring) o air bronchogram – can see bronchus clearly because alveoli are filled with something (consolidation or atelectasis, differentiate by clinical f indings) . if see bronchograms, can’t be due to something plugging up bronchus . An air bronchogram is a tubular outline of an airway made visible by filling of the surrounding alveoli by fluid or inflammat ory exudates. . Six causes of air bronchograms are; lung consolidation, pulmonary edema, nonobstructive pulmonary atelectasis, severe interst itial disease, neoplasm, and normal expiration. o Any time you see loss of volume, post-obstructive pneumonias can occur  MUST obtain follow-up x-ray 4-6 weeks o Loss of volume = atelectasis due to endobronchial obstruction lesion (e.g. carcinoma) o Look at level of diaphragms for evidence of loss of volume. Can also have mediastinal shifting due to loss of volume. o *If see heart right border, RIGHT MIDDLE LOBE normal. o Can see growth plates in humeral heads  signifies child o Ex. RLL pneumonia --- can see heart border on lateral CXR (posterior border of LV) o Lingula blocks left horder border

 Elevated left hemidiaphragm o Loss of volume - atelectasis, PNA o Abdomen mass pushing it up o Ascites (should push up both) o Paralyzed left hemidiaphragm

 Tension Pneumothorax ○ If ever a question of pneumothorax, order an expiratory CXR. Tension pneumo decreases venous return o Air inside the pleura, collapses lung . See line of visceral pleura ○ Mediastinal shift ○ Bigger than you suspect  totally straight line – think hydropneumothorax (or hemopneumothorax if see bullets) o Air fluid line- straight line

 Can have bullous emphysema - can grow large enough to cause compression of the lung

 COPD o Beyond 10 ribs = obstructive disease

 Mediastinal emphysema (air in mediastinum = pneumomediastinum) – can be caused by esophageal tear or tracheal rupture, iatrogenic from procedure, idiopathic o do a water soluble contrast esophagram if suspect tear o medical emergency because can lead to mediastinitis

 Epiglottitis – thumb sign, steeple sign

 Pleural Effusion o opacification of the left hemithorax – due to large amount of fluid, with shift of mediastinum  likely due to pleural effusion . meniscus line – pleural effusion fluid . PA position: need 200-500mL of fluid to blunt costophrenic sulcus . Lateral: 150mL to blunt costophrenic angle . If suspect small amounts of fluid in pleural space can get decubitus film . If suspect pleural effusion on right, get right lateral decubitus. If suspect pneumo on right, get left lateral decubitus. . Effusion is fluid in a potential space, there is no air there normally

 Can have shift of mediastinum to side of opacification  loss of volume (e.g. left pneumonectomy)

Rotations Page 5 Can have shift of mediastinum to side of opacification  loss of volume (e.g. left pneumonectomy)

 Masses o Mass (>3cm) vs nodule (<3cm) o Describe characteristics: density (does it contain calcium  benign, inflammatory process with dystrophic calcification). Other examples: describing mass: well circumscribed, smooth and uniform shard borders or irregular spiculated borders or lobulated borders, uniformly dense, speckl ed calcification, ring like, necrosis or cavitation (malignancies break down and run out of blood supply) . When you see a nodule or a mass in the lung, check to see if they have older films . A lesion that has demonstrated no change over a period of two years is considered to be benign . Ghon’s complex: calcification in hilum (likely to have calcifications in periphery as well) . Granulomas calcify . If not as dense, is likely tissue density instead of calcification. o If new, will need to biopsy. If biopsy and malignant, do CT scan to check for metastasis o Irregularly shaped lesion that infiltrates into surrounding tissue; air in center so know it is cavitating. . It can be a tumor or a lung abscess (fever, white count, etc). If see fissure elevated, have loss of volume. (horizontal fissure is bowed up) . When have irregular mass and loss of volume, likely tumor (pneumonias do not often give loss of volume) . Air in middle of lesion is necrosis

o Alveolar vs. interstitial processes . Alveolar processes are acute - PNA . Fluffy, white, not well defined . Interstitium- chronic- fibrosis

 Cavities o Thin-walled cavity: bleb, bullae, coccidiomycoses (grape-skin cavity) o Thick-walled cavity (fairly well-circumscribed): granulomatous disease, histoplasmosis (ohio), blastomycosis, TB, fungal diseases o Thick-wall and lobulated centrally – squamous cell carcinoma  NEVER drain a lung abscess because can lead to an empyema (infection in the pleural space, which you have to drain); tx abscess with antibiotics

 Mediastinum o Ant mediastinum – retrosternal goiter, lymphoma, thymus, thyroid, lipoma, germ cell tumors (teratoma), diaphragmatic hernias (lumbocostal, hiatal) . 4 T's (teratoma, thymus, thyroid, terrible lymphoma) . `Thymoma- Myasthenia Gravis (80-20) ---what percentage of people have thymoma in MG - 20% o post mediastinum – neurogenic tumors (schwanomma), esophagus (diverticulum, neoplasm), diaphragmatic hernia, germ cell tumor (rare) o middle mediastinum – enlarged LNs, cardiomegaly, vascular aneurysms, cyst (eg pericardial, GI, bronchial)

 sarcoidosis – paratracheal adenopathy, bilateral hilar adenopathy  hilar adeopathy can also be lymphoma  multiple nodules of varying sizes – almost always metastases o Vs multiple nodules on same side of chest (granulomatous disease)  Posterior segment of upper lobe (avg pt) and superior segment of lower lobe: think TB (old) o Elevated right hemidiaphragm - loss of volume o When also affecting the vertebral column  Pott’s disease  Aspergillosis: fungus ball in cavity

5 Categories: Congenital, trauma, infectious, neoplastic, everything else (metabolic)

Other: Direct signs of collapse indicate diminished lung volume:

1) Septae will be displaced TOWARD the collapsed lung

2) The lung will be more radioopaque due to loss of air.

3) The bronchi will appear crowded together.

Rotations Page 6 3) The bronchi will appear crowded together.

Indirect signs of collapse:

1) Hilum/Mediastinum will be displaced TOWARD the collapsed lung.

2) Ipsilateral hemidiaphragm will be elevated.

3) Rib cage size will appear diminished. (Compare with old films!)

4) Compensatory emphysema:contralateral lung appears more radiolucent.

Patterns of collapse: Lobe Direction of collapse Shift of fissures RUL/LUL Superiorly, medially, anteriorly On right, minor fissure shifts upward and medially (PA) RML Inferiorly and medially Minor fissure shifts downward (PA) RLL/LLL Inferiorly, medially, posteriorly Major/oblique fissures shift downward and backward (LAT)

HEART

 can see calcium in intima of aortic aneurysm o Atherosclerosis of intima  can see prominent ascending aorta on RSB (Marfan’s if 6’6”, syphilis rare, post-obstructive aortic dilatation, atherosclerosis) o Aortic stenosis  CHF with pulmonary edema; CAD/ischemic myopathy is most common cause of pump failure o Normally can see hilar vessels o Pulm edema- see bat wing configuration o Nl LVEDP - <12  Increased venous pattern in the apical segments (cephalization) (increased in blood flow to the upper lung veins) (cephalization goes away if patient lays down?) o Vasoconstriction around lower lobe veins shunts blood to the upper lobe veins o Fluid around vessels cause perivascular cuffing; mediated by oncotic and osmotic forces o will eventually lead to interstitial fluid leading to kerley b lines (lymphatics taking fluid away); kerley b lines are best seen in lower corners of the film , horizontal lines . Patient gets Paroxysmal nocturnal dyspnea . Will hear a wheeze b/c there is fluid in interstitium = CARDIAC ASTHMA . LV pressure 18-20 . Then see Frank pulmonary edema (pressure 24-25) - fluid everywhere including the alveoli . Fluid gets dumped into pleural space --> pleural effusion . (EF = percentage of blood ejected in each stroke---decreased in HF)  MR: holosystolic murmur at apex radiating toward axilla. See left ventricle and left atrial enlargement o Elevation of left main stem bronchus (normal angle should be about 70 degrees)  Can get fluid in pericardial space – pericardial effusion (dx by ECHO) o Globular heart (water bottle shaped)

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 MITRAL STENOSIS: If left ventricle is normal but left atrium is enlarged, likely Mitral Stenosis (diastolic murmur); sometimes can see left atrium on right side of heart. Also see large PA due to secondary pulmonary HTN

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 *Left atrium enlargement from mitral regurgitation and mitral stenosis o Mitral stenosis - diastolic murmur . LV not enlarged o Mitral regurgitation- holosystolic murmur radiating to axilla . Left ventricle is enlarged  **Left border- aortic knob, main pulmonary artery, left atrial appendage (left atrium), Left ventricle  Unable to see arch of aorta o Coarctation of aorta o Notching of the ribs  normal pacemaker should be in apex of right ventricle o Trabeculated o ICD o Bipolar pacer- two leads

Rotations Page 7 o Bipolar pacer- two leads

 Central line complications: thrombosis, infection, PTX (central lines should go in distal superior vena cava just proximal to the entrance into the entrance of the right atria- 2 cm above junction of SVC and RA) - needs to be past valve in brachiocephalic o Right atrium not a good place b/c tricuspid valve is there and can cause arrhythmia ; non infectious endocarditis

Other - VSD o RV and LA will be enlarged - ASD o LA is normal to small o RA will be enlarged o RV will be enlarged - PDA o LA enlarged and LV enlarged What Radiology tests to order and when!  ACR website has “appropriateness criteria” - clinical modules  GI o Acute massive hemorrhage- significant bloody aspirate, hematemesis, hematchoezia or severe melana o Upper GI bleeding - s1. stabilize, 2. endoscopy . Ulcers, varices are most common causes . Endoscopy - to find ulcer and sclerose it or varix o Lower GI bleeding . MCC- diverticulosis (also AVM) . Technetium labeled Radionucleotide RBC scans  LLQ - left hemicolectomy . Colonoscopy vs barium enema . Enteroclysis for small bowel studies (usually do to polyps---tube down inject barium to see where it goes) o Angiography . Diagnostic: AV malformations, angiodysplasia . Treatment  Chronic blood loss o Fe def anemia or positive stools for blood . Air contrast barium enema  Role of colonoscopy . Air contrast GI series . Small bowel study . Angiography  Diverticulitis o Symptoms: LLQ pain, fever, occasional diarrhea o CT abdomen AND pelvis – with and without contrast (delay imaging two hours after contrast) . With oral contrast and IV contrast  Gallbladder disease o U/S, HIDA scan . HIDA shows you if cystic duct is open or closed; drug tagged with radioactive  Body treats substance like bile ---if it goes into gallbladder you know the cystic duct is patent and does not have acute cholecystitis o Gall bladder wall thickening- 3mm or more is indicative of gall bladder wall inflammation o US- look for stones, wall thickening, cholecystic fluid  Urinary Tract o NON CONTRAST CT bc stone is white on x ray and contrast is same color o Calculi: helical CT most accurate o Obstructive uropathy: U/S will tell you size, configuration of kidneys, and if obstruction exists . Could do plain xray to see if you can see the stone . If small and can't see it it will pass by itself  Postmenopausal bleeding o History – question hormone use o U/S – transabdominal if question transvaginal o If questions remain, MR  Adnexal masses o U/S – transabdominal and/or transvaginal . Ectopic pregnancy (hormone levels, U/S with color Doppler imaging) o MR imaging  Chest lesions o Solitary pulmonary nodule . CXR (previous films, age, hx, nodule size and configuration) o CT o PET scanning (benign vs malignant); nodule has to be 2cm in size to be seen . Positive nodule must be biopsied b/c high probability of malignancy o Pulmonary Embolus . CXR (other causes), V/Q scan, spiral CT, angiography, role of MRA  suspect PE, before CTA do a plain film xray to rule out other causes  do v/q scan for pregnant patients, contrast allergy (half the amount of radiation in CTA)  Ventilation - breathe in radioactive xenon- perfusion- give tagged albumin to see if there is an area that doesn't perfuse  Acute stroke o NON CONTRAST MRI o Most strokes are embolic --- obstruction to blood vessel o MR after 24 hours o Angiography . Most often for therapy . Catheter into common carotid and inject tPa- helps prevent GI bleeding  Encephalitis o Differentiate b/w hemorrhage, abscess, tumor o MR imaging o If unavailable in area then CT with contrast  Sinusitis o Coronal CT (non contrast) o First 30 days you don't image o Imaging to see where blockage is so surgeon can go in  Low back pain o Don’t image unless red flags o If not better after 30 days- MR imaging

Rotations Page 8 o If not better after 30 days- MR imaging o MR imaging, CT, plain films only if trauma, lumbar discography o Fever (osteo), malignancy (mets), and trauma (compression fx) are red flags  Child Abuse o Skeletal survey . To include skull, chest, lumbar spine, and extremities (single large x-ray inadequatE) . Multiple fractures at different stages of healing . Most common are stripping of the periosteum and avulsions at growth plates (small avulsion fractures at metaphyses of bones) . View with suspicion- fracture in an ambulatory child; metaphyseal avulsion fractures

 LAO- right heart becomes more prominent  FLUID GIVES MENISCUS

ICU Lecture  reading ICU CXR o check it is an adequate film o check for tubes, lines, catheters . 30% placed incorrectly ICD- thick wire portion

HEART VALVES

Tricuspid and mitral valve below line Aortic and pulmonic above  struts of prosthetic valves go in direction of flow  endotracheal tube o End should be 4cm above the carina o complication of trach tubes – stricture, most common is aspiration pneumonia, atelectasis if placed too far and ends up in RMSB . Flexing head moves NG tube downward, could enter RMSB o cuff can press against trachea and can compress blood supply (to prevent this, drop cuff every hour); when drop it, secretion s accumulate above the cuff (can lead to aspiration pneumonia) o halfway between chorine and thoracic inlet

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. A portable chest x-ray and close-up of a properly placed endotracheal tube (arrows) and location of carina (^).  Chest tubes o Removing air or fluid o PTX- up higher b/c air up higher o Fluid- lower  Central Line o The intravascular volume status of critically ill patients is crucial to their management. A CVP can be obtained directly via central vein catheters placed either through the subclavian veins or the internal jugular veins. Similarly, intravenous catheters may be used to infuse large volumes over lon ger periods of times with little chance of thrombosis. o Ideally the catheter tip should lie between the most proximal venous valves of the subclavian or jugular veins and the right atrium. o How far from the brachiocephalic vein are these valves? o Approximately 2.5 cm from where they join to form the brachiocephalic vein. Usually the last valve in the subclavian vein is at the level of the anterior portion of the first rib. Therefore, the tip should be medial to this point.

Rotations Page 9 Therefore, the tip should be medial to this point.

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 Dophoff tube o thin tube used for feeding with radiopaque end (metal tip) o Smaller  Swan ganz catheter o should be in either right of left pulmonary artery at the edge of the cardiac shadow o Can be inserted in femoral, subclavian or jugular o Triple lumen o 2 complications: thrombosis of vessel or hemorrhage o Need to decompress balloon after you wedge the catheter, otherwise will occlude blood flow and create a wedge -shaped infarct

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 After open heart surgery, want to put in mediastinal drains (otherwise accumulation of blood can cause tamponade) o Underneath heart on pleural surface

Film - - Cannot see through the left heart to the pulmonary vessels - Large white thing behind heart- not pleural fluid b/c can see costophrenic sulcus - could be consolidation or atelectasis of left lower lobe - PNA vs. atelectasis - clinical difference

 ARDS – o damage to type II pneumocytes and endothelium of alveoli, fluid leaks across cell membrane  PAS positive membrane  can’t oxygenate o Sepsis, hypoxia, trauma, shock, hypovolemia o Patchy alveolar infiltrates

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 alveolar disease – looks like patchy clouds in the lung  interstitial disease – looks like linear pattern  Atelectasis o fissures will be moved over o do not confuse with fluid o often due to mucus plugging o Radiographic Appearance of Atelectasis . Radiographically, atelectasis may vary from complete lung collapse to relatively normal-appearing lungs. . For example, acute mucus plugging may cause only a slight diffuse reduction in lobar or lung volume without visible opacity. Nevertheless, the physiologic effects can be significant. In the so called mucus plugging syndrome, the association of sudden hypoxia with a normal or quasi-normal chest radiograph can lead to the suspicion of a pulmonary embolus. Mild atelectasis usually takes the form of minimal basilar shadowing or linear streaks (subsegmental or "discoid" atelectasis) and may not be physiologically significant. . Atelectasis may also appear similar to pulmonary consolidation (dense opacification of all or a portion of a lung due to filling of air spaces by abnormal material), making it difficult to distinguish from pneumonia or other causes of consolidation. The distinction between atelectasis and other causes of consolidation is important, and certain clues exist to aid in making that determination. Atelectasis will often respond to increased ventilation, while pneumonia, for example, will not. Crowding of vessels, shifting of structures such as interlobar fissures towards areas of lung volume loss and elevation of the hemidiaphragm suggests atelectasis. Another key for distinguishing b/w atelectasis and consolidation is recognition of the typical patterns that each pulmonary lobe follows whencollapsing.

Rotations Page 10 Right upper lobe atelectasis is easily detected as the lobe migrates superomedially toward the apex and mediastinum. The minor fissure elevates The left lung lacks a middle lobe and therefore a minor fissure, so left upper and the inferior border of the collapsed lobe is a well demarcated curvilinear lobe atelectasis presents a different picture from that of the right upper lobe border arcing from the hilum towards the apex with inferior concavity. Due collapse. The result is predominantly anterior shift of the upper lobe in left to reactive hyperaeration of the lower lobe, the lower lobe artery will often upper lobe collapse, with loss of the left upper cardiac border. The expanded be displaced superiorly on a frontal view. lower lobe will migrate to a location both superior and posterior to the upper lobe in order to occupy the vacated space. As the lower lobe expands, the lower lobe artery shifts superiorly. The left mainstem bronchus also rotates to a nearly horizontal position. LEFT UPPER LOBE- blur left of heart border

Right middle lobe atelectasis is difficult to detect in the AP film (left). The lateral (right), though, shows a marked decrease in the distance between the horizontal and oblique fissures.

Right middle lobe atelectasis may cause minimal changes on the frontal chest film. A loss of definition of the right heart border is the key finding. Right middle lobe collapse is usually more easily seen in the lateral view. The horizontal and lower portion of the major fissures start to approximate with increasing opacity leading to a wedge of opacity pointing to the hilum. Like other cases of atelectasis, this collapse may by confused with right middle lobe pneumonia.

 Pneumothorax o deep sulcus sign: will see costophrenic angle go very deep o barotrauma – trauma induced by the pressure of mechanical ventilation o want to have CT near apex o In the supine patient, intrapleural air rises anteriorly and medially, often making the diagnosis of pneumothorax difficult. o ORDER LLD left side down for Right pneumothorax

 Tension Pneumothorax

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 Tracheostomy tube o Balloon at end of tube - should be same width as trachea (not larger) o Can lead to stricture  NG tube o has end hole and side hole (in case end hole gets blocked) o for feeding – put post or close to pylorus o for decompression – past LES is fine  Intra-aortic balloon pump o want marker to be just distal to the subclavian

Rotations Page 11 o

 bilateral patchy lower lobe infiltrates – almost always aspiration pneumonia especially in ICU

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o  nice air bronchograms = pneumonia, not atelectasis o Balloon tracheostomy dropped down  hemoptysis: TB, bronchitis/bronchiectasis, bronchial carcinoma, fungal infection  Mediastinal Emphysema

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 Pneumopericardium

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o A. Portable upright chest x-ray before aspiration; B. Chest x-ray 1 hour after aspiration, showing bilateral diffuse alveolar infiltrates, worse at the bases on the right side

 Heart Failure

 Other

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o ET tube - Children halfway b/w carina and and thoracic inlet o AORTA- POSTERIOR SEGMENT Abdomen  abdominal upright film o rotation: look at vertebrae and ribs. o Supine film . Should see bottom of pubis o Erect . Should see diaphragms

Rotations Page 12 . Should see diaphragms

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 Gas patterns o look for small or large bowel obstruction which would lead to ischemia to necrosis to perforation o do both supine and erect films when looking for obstruction o if pt can’t stand, do AP and left lateral decubitus o plicae of small bowel go all the wall across o haustra of large bowel go part of the wall across the wall . normal colon can be 5-6 cm in size. Cecum about 10cm . ascending and descending are retroperitoneal . transverse and sigmoid are intraperitoneal  Obstruction o Determine large vs small o Mechanical vs ileus . Mechanical . air fluid levels at different heights means that there is tone present (so you can be certain this is a mechanical obstruction as opposed to ileus)

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 Paralytic Ileus

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 Large Bowel Osbruction o May get dilated small bowel b/c of incompetent ileo-cecal valve o Sigmoid Volvulus . Sigmoid Volvulus with a markedly distended loop of colon in the midline of the abdomen. There is a thin vertical band of tissue pointing toward the left upper quadrant. This tissue band represents the medial walls of the twisted colon and is present in 60-70% of patients. The colon converges toward the pelvis. There is no air in the rectum due to the obstruction.

Rotations Page 13 o

o LBO- Sigmoid Carcinoma

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 Large spleen o ITP, lymphoma, spherocytosis, CLL o Pushes colon medially  If enlarged kidney o push descending colon lateral

 most common visceral structures that rupture: gastric/duodenal ulcer  Pyloric ulcer-- can obstruct stomach --- get enlarged stomach o Delayed empyting - gastroparesis - in diabetic  Case - PANCREATIC PSEUDOCYST o n/v/ abdominal pain o Soft tissue mass - 8 cm rounded mass with good sharp borders in LUQ o LUQ- It could be the pancreas, spleen , kidney, adrenal, stomach, or abdominal wall.

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 Case - pancreatic pseudocyst o Mass- calcified 6-7 cm rounded mass LUQ o ? Kidney cyst - do oblique and see if it moves with kidney -- could do US o Aneurysm - Splenic artery aneurysm (females)  Case - Gallstones + pseudocysts in ducts = Gallstone Pancreatitis o Abdominal pain/ nausea/ vomiting o Calcifications in RUQ . Gallstones (20% calficified) . Other calcifications look like in the ducts - pnacreatic duct calcifications o Something pressing on stomach . Large soft tissue density . Also calcifications on the right side o Erect film . Can see air fluid levels . Calcifications fell down inside something = Gallstones

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 Case = Appendicitis o RLQ pain + calcifications o Pathophys- obstruction at neck of appendix  Case - Aortic Abdominal Aneurysm o Abdominal pain, N/V

Rotations Page 14 o Abdominal pain, N/V o Calcifications

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 Pneumotosis Intestinalis- Intramural Air o air in the wall of the bowel, caused by ischemia due to obstruction o will see both luminal and serosal side of bowel o NICU babies - necrotizing enterocolitis - air in wall of bowel

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 Necrotizing enterocolitis with perforation of the terminal ileum.

 Free Air o Pneumoperitoneum

 Can see retroperitoneal free air around kindney o ERCP, trauma  Kidney above liver -  Uterine Fibroids o uterine fibroids will calcify  Soft Tissue Abscess o Abscess - Lesser sac abscess secondary to pancreatitis o The presence of gas and fluid in the lesser sac is usually from a pancreatic abscess, but other organs must be considered suc h as the duodenum, stomach, or an enteric fistula.

Rotations Page 15 o Abscess in uterus- endometritis  air forming abscess looks like cloudy/puffy structure  Volvulus o Sigmoid (intraperitoneal)

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o Cecum can also volvulate  when looking for free air – left lateral decub

Ultrasound  best to do ultrasound over fluid filled area (not lung or bone)  we use the terms hypoechogenicty (black), hyperechogenic (white); isoechoic - muscle -- normal  Anechoic - fluid filled - gallbladder - no echo  TIA - check for carotid doppler  Cannot be used for bowel  Uses o Liver . Mass lesions . Portal vein flow o Gallbladder o Kidney . Obstruction/hydronephrosis o Aorta o Misc . Fluid in abdomen  Hepatic vein to IVC  Decrease flow by 50%--- need to have lumen narrowed by 70%  blood vessels/fluid will be black  cant see bowel well  can see hepatic vein thrombosis (budd chiari)  Benign cyst – anechogenic, smooth borders, increased through transmission - increased echoes  mass in the breast, thyroid and scrotum are good for distinguishing between solid and cystic lesion  Advantage b/c real time so you can have patient sit up to differentiate GB stone vs polyp

GI  video fluoro studies for swallowing problems  double contrast GI is done when you are looking for abnormalities in mucosa  when small bowel gets inflamed, it gets spikey like picket fence  dysphagia: o tumor, diverticulum, schatzkis ring, stricture, achalasia, eosinophilic esophagitis, ulcers o Do swallowing function video study  Esophagus o Barium swallow or esophagram - study of esophagus o Done with single or double contrast . Double contrast- high density barium (sour cream consistency)- coats mucosa so better view of mucosa  If patient is cooperative the standard test is DOUBLE CONTRAST GI study  For patient who cannot turn, follow orders, etc- SINGLE CONTRAST GI study o Don't visualize mucosa as well

Rotations Page 16  Diverticula

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 Zenkers Diverticulum

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 Esophageal Varices

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 Esophagitis

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 Duodenal ulcer

Rotations Page 17 Duodenal ulcer

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o Contrast goes into hole in mucosa)  Esophageal Tumor

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 Adenocarcinoma of the Stomach

 Polyps

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 Esophagus - 12 mm or less - need to operate o Barium pill that is exactly 12 mm in diameter o Esophagram with Barium pill Study  Diaphragmatic Hernia

o Malignancy . Overhanging shelf . (stricture tapers)

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 Barretts Esophagus

Rotations Page 18 Barretts Esophagus

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o Barrett esophagus with a midesophageal stricture and a reticular pattern. Double -contrast esophagogram shows a focal area of mild narrowing in the midesophagus (black arrow). Note also the distinctive reticular pattern that extends distally a considerable distance from the stricture (approxi mately to the level indicated by the white arrow). This reticular pattern is thought to result from intestinal metaplasia in Barrett mucosa.

 Contrast o Barium for esophagus on down  thickening of colon wall and blood in submucosa – ischemic colitis o shaggy exudative yellow crap – C. diff

 Ulcerative Colitis o Lead pipe appearnce

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 Multiple small lesions in colon with no haustra and lead pipe appearance – ulcerative colitis o UC generally starts in left colon (rectum) and Crohn’s in the right colon (terminal ileum) o UC has tiny shallow ulcers and Crohn’s has large deep ulcers that penetrates o UC rarely has fistulas whereas Crohn’s often has fistulas o UC is continuous and Crohn’s has skip lesions o UC has high rate of malignancy and Crohn’s has lower . Crohn’s have abnormalities of sacroiliac joints and in biliary tree; can manifest anywhere in GI tract . UC is limited to the colon o Both happen in the young but Crohn’s is bimodal and can present later in life as well  Crohns Disease o String sign

Enterocolic Fistula

 Men can get fistula between colon and bladder and get air in the urine. Women do not because uterus in between.  When see narrowing or structuring in UC, think cancer  Reserve CT for complication search (fistula, abscesses, etc)  Barium study is study of choice for Crohns and colonscopy for UC  Can see apple core lesions – carcinoma of the colon  HIDA

. Normal filling o give patient IV drug tagged with tecnichium which is excreted like bile (get outline of liver); if see bile ducts, means the y must be dilated o Dilated common bile duct and dilated pancreatic duct  ampulla of Vater obstruction o Double Duct sign . Dilated pancreatic and common bile duct  Liver o Metastatic disease

Rotations Page 19 Metastatic disease

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 Splenic vein runs on dorsal aspect of spleen (lesions of the pancreas like carcinoma or pseudocyst can obstruct the splenic vein and can lead to varices) CT

Rotations Page 20  http://fitsweb.uchc.edu/ctanatomy/abdomen/axial.html  same densities but now we can distinguish between water and soft tissue  can see enhancing (with blood supply, lighter) with darker fluid in middle – likely a pseudocyst  contrast o barium – inert o gastrographin is water soluble oral contrast o iodine tagged to inulin (for kidney) or other substances o ionic – dissociate into component molecules (increased side effects) o non-ionic – bound to an organic compound; less side effects o Gadolinium for MR Contrast . Need to know GFR . If GFR less than 30 it is CONTRAINDICATED to give patient contrast during MRI . May develop diffuse systemic sclerosis . 30-60 need very good reason to give contrast - life or death situation . GFR > 60 to be safe o Stop metformin 12-24 hours before giving contrast and at least 24 hrs after giving contrast  IV contrast uses: anatomic clarification, assess perfusion, angiography, lesion characterization, assess defects in BBB, assess for extravasation o MUST CHECK PATIENT’S CREATININE  Tumor enhances b/c it has blood vessels; a cyst won't o e.g. cecum enhancing - most likely a tumor  to do IV contrast CT pt cannot have Cr over 2, between 1.5-2 better have a good reason for CT  best way to prevent AKI is hydration  patient must be off metformin for at least 12 hours prior to CT and keep pt off for 48h after or patients will often go into lactic acidosis  gadolinium is the contrast used in MR must be tagged to organic substance, must check renal fx o if GFR is under 30ml/h it is contraindicated to give contrast o between 30-60ml/h should be a good reason  non contrast CT – looking for head bleed and looking for stones

ER/MSK  to clear C-spine: cross table lateral through collar,----then can do other views A/P, adontoid  Abdominal/Pelvic o AAA – CT/US o renal colic – non contrast CT/US/IVP o cholecystitis – US/HIDA o appendicitis – CT/US/plain film o ectopic – US o testicular torsion – US/nuclear o trauma – CT/US  SKELETAL RADIOLOGY o ankle: A/P, lateral, oblique’

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o hip: A/O, frog leg, lateral o Shoulder

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o Wrist . Colles Fracture

Rotations Page 21 . Colles Fracture

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o soft tissue swelling is often an indication for the location of a fracture o Fracture Base of 5th Metatarsal

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o Fracture Descriptions . Number of fracture framents (simple or comminuted (more than 1)) . Direction of fracture line (transverse right across bone, oblique diagonally, or spiral)  Transverse: force applied perpendicular to long axis of bone; fracture occurs at side of force . Relationship of one fragment to another (displacement, angulation, shortening, and rotation – determines whether will splint or need OR) . Open to atmosphere (outside) – closed or open (compound) o if you think kid has fracture, splint for 7-10d and then re-xray o Hip fractures

. . Subcapital (base of head) . Most common

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. Femoral neck  If fracture subcapital or higher part of neck, will damage middle circumflex and can develop avascular necrosis  Easier to fix  If this is the case, they can go in and replace it right away . Intratrochanteric . Good blood supply still, so go in and nail it

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o Green stick/buckle fracture in children – bendable bones . In children, get a film in the view that you see the abnormality, but look at other side for comparison

Rotations Page 22 In children, get a film in the view that you see the abnormality, but look at other side for comparison

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o increased bone density think avascular necrosis (femoral head and scaphoid) o Abnormal fat pad . Most likely an occult fracture

o Dislocations . Anterior vs. posterior o Rotator Cuff tear o Scapho Lunate o Hand Bones

o Lunate dislocation

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o Children . Look for epiphysis plate fractures . Will cause growth problems

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o Mallet Finger

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o Spinal Anatomy

Rotations Page 23 . Space should not be more than 3 mm . don’t miss a c2 fracture of dens . Can happen in RA o ACL tear

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o liss-frank fracture – increased space between first and second metatarsal o cortical thickening  Paget’s; marketedly elevated alkaline phosphatase (indicates marked anabolic overgrowth in bone)

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. Frontal radiograph of the pelvis shows marked sclerosis of the sacroiliac joints, as well as the iliac bones, left greater than right (correlating with the bone scan findings). Additionally, there is severe osteoarthrosis of the hip joints, with joint space narrowing and remodeling of the femoral heads. o Sickle cell: 17yo with enlarged heart due to anemia and high output failure, dense white bone due to sickling . Dense ribs . Cortical infarcts o Arthritis . degenerative arthritis – most common bone abnormality (osteophytes, narrowed joint spaces, sclerosis) □ involves DIP joints (in contrast to rheumatoid, which involves PIP) . rheumatoid – erosions in early rheumatoid . subchondral increased lucency/destruction and sclerosis characteristic ofaseptic necrosis . Scleroderma

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o Metastatic disease / pathologic fracture o Increased bone density = . Osteoblastic metastases or avascular necrosis (dead bone) o Neurofibroma o Bone tumors . irregularity with stuff growing out into soft tissues – osteosarcoma . bone is irregular and periosteum is elevated; one area growing into soft tissue – osteoid . tumor living in epiphysis – osteoblastoma . in middle phalanx along medial aspect, can see sub periosteal resorption associated with hyperparathyroidism . benign tumor expands bone but has a sclerotic rim (body walls it off) □ Well defined edges . Malignant Tumor □ Cortex eroding, edges not well defined

Rotations Page 24 o Deposition Arthritis of abnormal substance in joint . Gout – . inability to metabolize purines, so uric acid is deposited in soft tissues, classically in synovium; classically in first pha lanx o thin periosteum in fingers (lacy-like) – osteoporosis (not enough mineral in bone) o thickening of bone can be osteoblastic metastases (eg prostate) o SCFE . draw line perpendicular to middle; if femoral head extends outside of line, SCFE  can lead to avascular necrosis . Normal - head comes over neck

. Klein lines are drawn along the superior cortex of the femoral neck. A normal Klein line will intersect the epiphysis. An abnormal Klein line does not intersect the epiphysis, as the femoral neck has moved proximally and anteriorly relative to the epiphysis

o Scapula Fracture

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IR  INTRAARTERIAL AND INTRAVENOUS CONTRAST o Angiograms (arteriograms and venograms) are obtained by injection of radioopaque contrast material directly into a blood vess el via a needle or catheter. The contrast is comprised of high density iodine, which attenuates the x-ray beam and makes the lumen of the blood vessel visible. The iodine is subsequently filtered through the kidneys and excrete d in the urine. o The fluoroscopic images are displayed digitally, and can be manipulated such that the vessel lumen appears white or black. Th e image on the right is "subtracted" which means that the bones and other structures have been subtracted from the image so that only the blood vessels are seen. o The forward movement of the contrast bolus that occurs concurrent with venous return (venogram) or arterial pulsation (arteri ogram) is observed fluoroscopically. Without the injected x-ray dye, the blood vessels would not be visible.

 Intra-arterial infusion therapy o Hemorrhage control o Thrombolysis o Chemotherapy infusion o Relief of vascular spasm  Vessel Occlusion o Clot from somewhere else- Heart- Afib o Atherosclerosis - vessel thrombosis  Occlusion Therapy o Hemorrhage o AV malformations and fistulas o Tumors o Organ ablation o Varicoceles - more common on L than right o IVC filters  Percutaneous Trnasluminal angioplasty o Peripheral vascular system o Renal arteries o Distal aorta o Visceral arteries  Need 70% narrowing to reduce blood flow by 50%  Need to decrease flow by 70% to feel symptoms  Thoracentesis o Stay at top of rib b/c underneath rib is artery, nerve, vein o Could create a fistula  check GFR before giving gadolinium  most common cause of IVC filter is recurrent DVT/PE that fails medical management  IVC Filter o must be distal to renal vein; don’t want clot to propogate back into kidney o Once open it additional clots can occur so don't want to clot renal veins  Fibromuscular Hyperplasia o String of beads sign  Subclavian steal syndrome o retrograde flow in vertebral artery; due to a proximal stenosis (narrowing) and/or occlusion of the subclavian artery. The arm may be supplied by blood flowing in a retrograde direction down the vertebral artery at the expense of the vertebrobasilar circulation.

Rotations Page 25 retrograde direction down the vertebral artery at the expense of the vertebrobasilar circulation.

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o Contrast-enhanced magnetic resonance angiogram showing the aortic arch (AA) and the arch vessels in a right anterior oblique projectio n. The proximal segment of the left subclavian artery (LSA) does not enhance and is occluded. The arrowhead indicates the site of origin of the LSA. BCA indicate s brachiocephalic artery;

Ileocolic is the last branch of SMA- goes to ileo-cecum w Celiac artery branches

Aortic arch and subclavian angiogram • The x-ray dye is injected through a catheter which is located in the aortic arch. Any evaluation of the upper extremity

Rotations Page 26 • The x-ray dye is injected through a catheter which is located in the aortic arch. Any evaluation of the upper extremity arteries must include an evaluation of the aortic arch and the brachiocephalic trunk. • The aortic arch can be seen, with its three branches: the brachiocephalic trunk, the left common carotid and the left subclavian arteries. • The brachiocephalic trunk divides into the right common carotid and the right subclavian arteries. • The subclavian artery give off several branches, including the vertebral arteries. The subclavian artery becomes the axillary artery at the lateral border of the first rib.

http://www.dartmouth.edu/~anatomy/Head-neck/vessels/angiograms/CTAarch.htm Nuclear Medicine  don’t need to worry about harming liver or kidneys because loading dose is so small  can pick up stress fractures  Checking for further lesions - osteosarcoma--- may change plans for chemo/radiation/ surgical candidacy  Bony metastasis - seen in prostate cancer, breast cancer  To look for edema in bone marrow - MRI - but cannot do a whole body MRI study  Galium 67 citrate- spine infection, interstitial nephritis  Indium labeled WBC- soft tissue infections- thoracic pelvic region  Technetium labeled- good for extremities

Neuroimaging

Rotations Page 27  Gray white junction helpful to tell health of brain

 Brain MIRI

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o T1 . Very good for looking at anatomy o T2 o T1 Gadolinium o Flair . Compare cortex to ventricle? o Central sulcus sign

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 Vasogenic edema o Neoplasm (GBM or met) o Cerebral abscess o Hematoma  Omega: site where hand is on homunculus o In front: frontal o Behind: parietal o Central sulcus is the first one that interrupts and goes deepest  Anterior commissure o Holes below = around CSF/vessels o Holes above = infarct  Most commonly injured nerve in head trauma is CN1 (olfactory)  Syrinx causes o Tumor o Trauma

Rotations Page 28 o Trauma o Congenital (eg Chiari malformation)  How to approach CT of the head o Is there geometric distortion? Is something the wrong size, shape, or position? o Soft tissue abnormality? o Abnormal enhancement?  Subdural hematoma (goes along skull); if not white, means old o Midline shift  Cerebral Amyloid Angiopathy

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o Sensitivity of GRE imaging for hemosiderin in an 80-year-old man with dementia that has progressed over the past 4 years. (a) Axial GRE MR image shows multiple foci of signal loss in cortical-subcortical locations. In a patient with a diagnosis of probable CAA, these foci are consistent with chronic microhemorrhages .

 Ventirculomegaly o Hydrocephalus (obstruction) o Volume loss (atrophy, surgical) o Congenital (never developed) o If both lateral and third ventricle are enlarged, obstruction is in aqueduct of Sylvius  aqueduct stenosis (post inflammatory?)

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. Magnetic resonance image obtained in a patient treated with ETV for hydrocephalus due to aqueductal stenosis, revealing an open sylvian aqueduct (arrow).

. Noncontrast axial head CT (A) and GRE (B) demonstrating microhemorrhages and lobar hemorrhage consistent with cerebral amyloid angiopathy.

o Meningiomas are isointense to brain parenchyma (so need contrast to see)

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o Meningitis . Leptominigiomia enhancement o MCA > PCA > ACA/PICA  Glioblastoma Multiforme

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 Medulloblastoma

Rotations Page 29 Medulloblastoma

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 Vestibular Schwanoma

 Chronic ischemic changes o Gliosis (proliferation of glial cells), encephalomalacia (hole in brain) o Loss of parenchymal volume  Scalp Lymphoma  Prolactionoma

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 Pinealoma

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 Ischemic change o Ischemic small vessel disease o Hypertensive vasculopathy o Branch vessel infarcts (MCA)

MCA infarct . DWI takes 30 minutes to show up

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o Embolic infarcts (often cardiac) . Often out in periphery . Subcortical white matter and adjacent cortex

Rotations Page 30 Subcortical white matter and adjacent cortex

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o Border zone infarcts (b/w MCA and ACA) / Watershed

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 Intracranial hemorrhage

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o Intra-axial or extra-axial? . Look for relationship to the cortex/skull . Widening of extra-axial space = extra axial o Extra-axial . Epidural, subdural, subarachnoid . Shape of collection? --- e.g. crescent . Smooth interface with brain (does it fill sulci)? . Does it respect (aka not cross) the sutures? . Epidural Hematoma □ Biconvex; most are middle meningeal; a/w with fracture

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. Subdural Hematoma □ Usually due to tearing of veins; no consistent a/w fractures □ Common in infants and elderly □ Crescent shape along surface of brain; crosses suture lines  Smooth interface with the brain □ Acute is bright white □ Iso to CSF = chronic  Chronic SDH becomes low density as the hemorrhage is further reabsorbed. It is usually uniformly low density but may be locul ated. Rebleeding often occurs and causes mixed density and fluid levels. □ Subacute  Subacute SDH may be difficult to visualize by CT because as the hemorrhage is reabsorbed it becomes isodense to normal gray m atter. A subacute SDH should be suspected when you identify shift of midline structures without an obvious mass. Giving contrast may help in diffic ult cases because the interface between the hematoma and the adjacent brain usually becomes more obvious due to enhancement of the dura and adjacen t vascular structures. Some of the notable characteristics of subacute SDH are: ◊ - Compressed lateral ventricle, Effaced sulci, White matter "buckling", Thick cortical "mantle"

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. Subarachnoid hemorrhage . Most commonly from trauma; also ruptured aneurysm . Blood in subarachnoid space, cisterns, and ventricles . Crosses sutures; fills sulci

Rotations Page 31 High density blood (arrowheads) fills the sulci over the right cerebral convexity in this subarachnoid hemorrhage. o Intra-axial (ICH) . Intra axial is a term that denotes lesions that are within the brain parenchyma, in contrast to extra axial, which describes lesions outside the brain, and intra ventricular, which denotes lesions within the ventricular system. . Is there associated trauma?  Contusion vs. diffuse axonal injury . If there is no known trauma:  Lobar hematoma or hypertensive hemorrhage (deep) . TRAUMA 1. Contusion  Half of intra-axial post traumatic lesions  Typically punctate or linear hemorrhages along gyri  Characteristic locations- 1/2 temporal lobes, 1/3 frontal lobes

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2. Diffuse Axonal Injuries  Seen with sudden accel/decel  Often at gray white junction  Typically lose conscoiusness at moment of injury  Hard to see on CT scan . NON TRAUMA 1. Lobar Hematoma a) Into extraaxial CSF space  Supratentorial hemorrhages  In patients over 55 most likely due to Cerebral amyloid angiopathy  Consider arterial vascular malformation, tumor and cavernous malformations in younger patients

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 Cavernous angioma- popcorn lesion

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 AVM

Arteriovenous malformation (AVM) of the brain. A CT scan of the posterior fossa demonstrating a hemorrhage in the fourth ventricle, with extension to the left cerebellum.

2. Hypertensive hemorrhage  Deep intracerebral hemorrhage ◊ Basal ganglia 60-65 ◊ Thalamus 15-25 ◊ Pons and Cerebellum

MRI  Non-ionizing radiation and non-invasive; low side effects  Based on spin of atoms (dependent on hydrogen nuclei)  T1: water is black, bone is white

Rotations Page 32  T1: water is black, bone is white o More like anatomy o When do head CT, use T1 o Vessels look black because of the flow o All post contrast sequences are T1  T2: water is white, bone is black o Very good for detecting abnormality; sensitive but not specific  Greatest advantage is better contrast resolution than CT, esp for soft tissue  Check GFR (>60, don’t worry about it; 30-60 need a REALLY good reason) o To avoid diffuse systemic sclerosis  Unit of magnetism = tessla  Three sequences that highlight the brain are T1, T2 and flair  Shoulder MRI

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 Knee o If see fibular head you know it is lateral

 Avascular Necrosis

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 Psoas o Inserts on lesser tronchanter  Tuboovarian Abscess

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Angiography

Rotations Page 33 Mammography  Mammomgraphy is the single most largest reason for lawsuit of radiologists  If woman has dense breast on mammogram, must have U/S  distribution of calcifications o grouped, cluster (5 calcifications in a 1cm) o pleomorphic o fine and branching  feel breast mass, first test do U/S for cystic or solid  if cystic it has to be anechoic, posterior wall is sharp, increased through transmission – don’t have to aspirate it unless it is painful

GU  look for kidney size, shape and position  nephrogram – outline of kidney  7-10minor calyces  there is peristalsis in the ureter  loss of volume – chronic infection/scarring, hydronephrosis  pyelonephritis – blunted calyx  renal cysts are very common  bilateral big kidneys – adult polycystic kidney disease, hydronephrosis, amyloid, renal vein thrombosis  small kidneys – atrophy from HTN, multiple infarcts, chronic pyelo  men are more likely to get strictures of urethra  one of the most common causes of hematuria in the elderly is transitional cell carcinoma  work up of pt with hematuria and renal mass = pre and post contrast ct  stones less than 6mm pass without intervention  calcification in the renal parenchyma – nephrocalcinosis  renal failure – first imaging study is ultrasound

Women’s Imaging  transabdominal U/S needs very distended bladder to see uterus  transvaginal U/S is more detailed but transabdominal is more broad view  endometrium can be up to 1.5cm in premenopausal female  post menopausal woman should have endometrial stripe  ovarian follicles are not cysts/tumors o thick wall, unilocular, no papillae  in secretory phase, avoid drastic measures, rescan later  ovarian carcinomas are complex, thick walled

Radiation Oncology

Rotations Page 34