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106 Cards in this Set
- Front
- Back
Head CT w/o:
When to order? Advantages? Disadvantages? |
look for blood.
No contraindication Cannot visualize posterior fossa/brain stem cuz of bony artifact |
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Head CT with:
When to order? Advantages? Disadvantages? |
When CT w/o is normal and you're looking for pathology like AVM, tumors, abscess, aneurisms
These lesions will ENHANCE cuz blood brain barrier is compromised. Contrast will obscure acute bleed. ORDER CT W/O FIRST |
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Subdural Hematoma:
Location? Cause? CT Findings? If found in kids? |
95% frontal parietal
Tear of bridging veins Crescent shape Suspect abuse |
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SDH Rule of threes
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Acute: hyperdense up to 3 days.
Subacute: isodense 3d - 3 wks Chronic: hypodense > 3 weeks |
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Epidural hematoma:
Location? Cause? CT Findings? |
75% temporalparietal region.
Middle meningeal artery. Usually assoc w/ fx, may cross midline, biconvex shape, "swirl sign"(mix of high and low density) = acute bleed. |
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Subarachnoid Hemorrhage
Location? Cause? CT Findings? |
Subarachnoid space.
trauma or aneurysm Hyperdensities in sulci or cisterns |
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Contusions:
Location? Cause? CT Findings? |
Frontal, Temporal, Dorsal Lateral Midbrain
Trauma A bunch of little round hyperdensities around edematous hypodensity areas in characteristic locations. |
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MC form of brain herniation
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Subfalciform
(shift off of midline, 3rd ventricle shifted as well) |
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MC cause of hydrocephalus in adults.
in Kids? |
meningitis and subarachnoid hemorhage.
congenital aquaductal stenosis |
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MC type of brain infarct?
Acute CT findings? Subacute findings? Chronic findings? |
MCA
Acute: MCA hyperdensity AND loss of insular stripe Wedge shaped hypodensity Hypodense with dilation of ventrical/sulci called "encephalomalacia" |
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2nd MC brain infarct?
least MC brain infarct? |
PCA
ACA, assoc w/ ICA occlusion (not emboli) |
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2nd MC brain infarct?
least MC brain infarct? |
PCA
ACA, assoc w/ ICA occlusion (not emboli) |
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CXR technique: 4 things you look for
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1. Penetration, can see intervertebral disk spaces
2. Rotation, clavicular heads even 3. Inspiration, 10-11 post ribs 4. Motion, no blurring |
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ABCDEF of CXR
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Airway, midline trachea
Bones, no fx Cardiac, enlarged? Diaphram, pleural effusions, free air Extras, lines/tubes Fields, clear lungs |
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Silhouette Sign
Golden S Sign Luftshichel Sign |
When two areas of similar density overlap.
Horizontal fissure of RUL takes an S appearance from underlying mass Lucency around aortic arch from LLL hyperinflation representing volume loss in LUL |
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Air bronchogram Sign
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When air is seen in the intrapulmonary bronchi due to surrounding consolidation by a pathological process outlying the bronchus. This may be seen in pneumonia, pulmonary edema, pulmonary infarcts, and certain lung diseases.
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Spine Sign
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On lateral view, thoracic vertebral
bodies should get darker as you move down toward the abdomen. If they get whiter, be suspicious of a lower lobe infiltrate |
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Unsure if lung nodule is benign. Next step?
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compare priors. If stable for >2yrs, it's benign. Consider CT for further eval.
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Lung Cavities:
Abscess vs Malignant vs Granuloma |
Abscess:
Thick walled, > 4 mm SMOOTH inner wall +/- air-fluid level Malignant: Thick walled, > 4 mm IRREGULAR, thick inner wall +/- air-fluid level Granuloma: Thick or thin walled (< 4 mm) NO air-fluid level |
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Anterior Mediastinal Mass
Causes (4Ts)? |
Thymoma (MC), Thyroid, Terrible lymphoma, Teratoma
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Middle Mediastinal Mass
Causes? |
Adenopathy (MC), duplication cyst, aortic aneurysm, hematoma, neoplasm, and esophageal lesions.
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Posterior Mediastinal Mass
Causes? If pt <2yo? If pt 18-20yo? |
Usually secondary to neurogenic causes
Neuroblastoma Neurofibroma Schwannomas Ganglioneuromas malignant neuroblastoma Benign |
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CHF Stage I on CXR
MCWP of ____mmHg |
Progressive cephalization, which means increased blood fl ow toward the top of the lung
10-20mmHg |
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CHF Stage II on CXR
MCWP of ____mmHg |
Thin white lines at the lung
bases extending from the periphery of the lung due to interstitial edema, known as Kerley B lines 20-25mmHg |
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CHF Stage III on CXR
MCWP of ____mmHg |
Increased opacity around the hila in a butterfly pattern referred to as “bat wings” appearance
>25mmHg |
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CHF Stage IV on CXR
MCWP of ____mmHg |
Bilateral interstitial infi ltrates and bilateral pleural effusions
>30mmHg |
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At least ____ cc of pleural fluid should be present to be seen on an upright chest x-ray.
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100
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Simple PTX
Tension PTX Skin Fold |
Very thin white line (visceral pleura), with no lung marking beyond that line.
The above findings with a contralateral mediastinal shift. The involved hemithorax is dark and expanded. Look for lung markings BEYOND the thick (as opposed to thin) line |
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Deep sulcus sign (image unavailable)
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This chest x-ray demonstrates a large right pneumothorax with widening and deepening of the right costophrenic angle, also known as the deep sulcus sign (arrow).
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Bilateral Pleural Calcification
Unilateral Pleural Calcification |
Asbestosis
Old empyema |
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Aortic Dissection
Type A vs Type B CXR? CT? |
A=ascending, sx tx needed
B=descending, med tx CXR=widened mediastinum, dilated aorta, cardiomeg CT=double lumen (false and true) |
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Aortic Transection on CXR
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Widened mediastinum >8cm
if this is only sign, specificity = <10% OTHER SIGNS INCLUDE obscured aortic knob abn paraaspinous stripe blood in apical lung (apical cap sign) trach dev to RIGHT |
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Hampton's Hump Sign
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If the embolism results in infarction, a wedge-shaped opacity in the periphery of the lung known as a Hampton hump may be seen.
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Sarcoidosis on CT and CXR
Stage 0 Stage 1 Stage 2 Stage 3 Stage 4 |
Normal
Bilat hilar enlargement Bilat hilar enlargement with infiltrate Pulm infiltrate Pulm fibrosis |
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Sarcoidosis vs TB
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Sarcoid has BILATERAL LN enlargement, and NON-caseating granulomas.
TB has UNILATERAL LN enlargement and caseating granulomas. |
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TB on CXR:
Primary Reactivted Miliary |
Primary TB: Focal middle or lower lobe infi ltrate with hilar lymph node enlargement
Reactivation TB: Occurs in the upper lobes and superior segment of the lower lobe. Nodular opacities are usually seen. This can progress to cavitations, empyema, and miliary TB Miliary TB: Multiple tiny nodules are diffusely spread throughout the lung. This can occur during or after the primary or reactivation stage. |
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ETT should be ____cm from carina
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2-6cm
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Abd XR
Indication? Advantage? Limitations? |
Bowel obs, viscus perf, foreign body ingestion
Cheap and quick Screening ONLY, other modalities often needed to confirm dx |
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Abd US
Indications? Advantage? Limitations? |
Gallbladder and hepatic pathology
Delineation and differentiation of intra-abdominal cystic structures Trauma; FAST (focused abdominal sonography in trauma) is a very useful tool in assessment of trauma patients Emerging role of endoscopic ultrasound in biliary and pancreatic pathologies Guiding procedures Doppler studies for evaluation of vascular structures Cheap, noninvasive, no contrast Operator dependent Inferior for assessment of bowel pathology due to artifact from air Lack of mucosal detail |
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Abd CT:
Indications? Limitations? |
Assessment of acute abdomen and to rule out conditions such as acute appendicitis, acute pancreatitis, small bowel obstruction, colitis.
Trauma CT angiograms for suspected vascular leaks, aneurysm, bowel infarctions CT enterography is being used for inflammatory bowel diseases (Crohn’s disease). Virtual CT colonoscopy: Not yet a very widely used tool Radiation, expensive, availability |
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MRI:
Pros/Cons |
Superior soft tissue detail
Excellent cross-sectional imaging tool for evaluation and staging of malignancies, especially rectal and esophageal, inflammatory and obstructive pathologies Higher cost Contraindicated in patients with metallic hardware Long imaging time Claustrophobia |
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Barium Swallow
Indication? |
Esophageal pathologies
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Single- or Double-Contrast Upper GI Series
INDICATIONS? |
Imaging of pharynx, esophagus, stomach, and duodenum
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Small Bowel Follow-Through Examination and Enteroclysis
INDICATIONS? |
Imaging of small intestinal and ileocecal pathologies
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Single- or Double-Contrast Enemas
INDICATIONS? |
Imaging of the large intestine
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Fistulograms and Sinograms
INDICATIONS? |
May be used in postoperative patients for assessment of fistulae and sinus tracts
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Endoscopy
INDICATIONS? |
Upper and lower GI endoscopy enable direct visualization and directed biopsies.
Endoscopic retrograde cholangiopancreaticography (ERCP) visualizes the hepatobiliary tree. |
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ERCP indications
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Diagnostic ERCP is indicated in JAUNDICE of unclear origin and suspected PANCREATIC DZ such as chronic pancreatitis and pseudocysts.
Primary approach for DRAINAGE and STENTING of benign and malignant biliary obstruction, the main advantage being that the liver need not be punctured. If the papilla cannot be cannulated or the obstruction cannot be passed with a guidewire, a percutaneous transhepatic approach may be tried. However, in difficult and postoperative cases, noninvasive methods such as magnetic resonance cholangiopancreatography (MRCP) are increasingly being used for evaluation. |
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Achalasia imaging?
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Barium Swallow
look for bird beak or rat tail appearance |
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ZENKER'S DIVERTICULUM
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barium esophagogram or endoscopy.
Barium esophagogram reveals a barium-filled outpouching in the region of the esophageal inlet |
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GI BLEED
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Upper GI endoscopy is the defi nitive test for diagnosis and appropriate intervention.
Barium upper GI series may be done if endoscopy is unavailable and may reveal collection of contrast within the ulcer crater. Gastritis and duodenitis are manifested by thickened folds. Other tests for further investigation include radionuclide studies and angiography. |
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SBO
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XR = screening
Advantages: Usually helpful in establishing diagnosis. In rare cases, may be able to define the point of transition. Disadvantages: Difficult to ascertain definitive etiology. Plain films are diagnostic in 50% to 60%, equivocal in 20% to 30%, and misleading in 10% to 20% of cases. CT: Advantages: Clear diagnosis in equivocal cases, detailed anatomy with definitive cause and point of transition, differentiating paralytic ileus from anatomic obstruction Goals of imaging: Establish a diagnosis: Air fluid levels, dilated bowel loops |
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Complete vs. incomplete SBO
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No bowel gas beyond the level of obstruction in a complete obstruction
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COLONIC OBSTRUCTION
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XR = initial
CT = confirm dx and ascertain underlying cause. Hypaque enema may be diagnostic as well as therapeutic. |
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INFECTIOUS COLITIS
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CT scan is the investigation of choice and reveals colonic WALL THICKENING
Plain x-ray may reveal bowel wall thickening or proximal bowel obstruction. |
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ULCERATIVE COLITIS
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Plain radiography can readily detect toxic megacolon, one of the serious complications.
Double-contrast barium enema can readily detect mucosal changes of ulcerative colitis, namely, mucosal thickening, irregularity, and superfi - cial ulceration. Colonoscopy is generally CONTRAINDICATED in ACUTE conditions, but is useful for direct visualization and obtaining specimen for histopathologic correlation. CT findings are NONSPECIFIC and include bowel wall thickening |
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CROHN'S
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small bowel follow-through, enteroclysis, CT enterography,
Barium enema No single test is diagnostic. Mucosal infl ammation with transmural penetration, ulcerations, strictures, skip lesions, abscess formation. |
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ISCHEMIC COLITIS
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Plain x-ray: Normal or may reveal PNEUMATOSIS in the bowel wall or
bowel distention. CT scan WITH oral AND intravenous contrast may be NORMAL in early cases. Findings are usually nonspecific and include bowel wall thickening. Occasionally, gas may be seen within the mesenteric vein. |
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Diverticular DZ
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Abdominal CT is the imaging modality of choice.
Look for air-filled mucosal outpouchings in the bowel wall. Diverticulitis is characterized by associated inflammation manifested by pericolonic stranding. |
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APPENDICITIS
Modality of choice? For pregnant women? |
Abdominal CT is imaging modality of choice.
Ultrasound or MRI |
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APPENDICITIS
Findings on ultrasonography |
diameter of > 6 mm, noncompressibility, lack of peristalsis, and periappendiceal fluid collection.
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MIDGUT VOLVULUS
CT Findings |
characteristic whirlpool sign, i.e., bowel loops and superior mesenteric vein wrapping around the superior mesenteric artery
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CECAL VOLVULUS
Initial test? Confirm? CT findings? |
Plain x-ray: Findings include displaced cecum, small and large bowel obstruction up to the point of torsion, and paucity of gas in the distal colon.
Hypaque enema (single contrast) may confirm the diagnosis and may also lead to reduction of the volved cecum. CT scan reveals the characteristic “swirl sign” |
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SIGMOID VOLVULUS
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Abdominal x-ray is usually diagnostic. It classically reveals double loop (pelvic colon) obstruction with varying degrees of proximal small bowel obstruction. The twisted dilated loop is located in the right side of the abdomen and forms a central double wall that converges in the right lower quadrant called the “coffee bean” sign.
Single-contrast barium enema is helpful in diagnosis in equivocal cases and may result in decompression and reduction. CT scan is useful for delineating complications like vascular ischemia. |
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Diverticular DZ
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Abdominal CT is the imaging modality of choice.
Look for air-filled mucosal outpouchings in the bowel wall. Diverticulitis is characterized by associated inflammation manifested by pericolonic stranding. |
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APPENDICITIS
Modality of choice? For pregnant women? |
Abdominal CT is imaging modality of choice.
Ultrasound or MRI |
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GALLSTONE DISEASE AND CHOLECYSTITIS
Initial? Limitations? |
Ultrasound: demonstrates multiple echogenic (bright) foci within a distended gallbladder with dense distal posterior acoustic dark shadowing (flashlight sign) suggestive of gallstones. Always look for associated dilatation and calculi within the biliary ductal system.
Limited exam with big body habitus, inadequate distention, or overlying bowel gas. Characteristic findings include thickened gallbladder wall, pericholecystic fluid, positive ultrasound, Murphy’s sign |
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Hepatobiliary iminodiacetic acid (HIDA) scan (cholescintigraphy)
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used when ultrasound is unavailable.
Tc-labeled iminodiacetic acid is injected via an IV catheter followed by sequential imaging. Hepatic uptake occurs within the first 15 minutes and the tracer reaches the duodenum in 1 hour. Obstructing gallstones are characterized by lack of uptake of the tracer in the gallbladder and the cystic duct. Gallbladder contraction can be assessed by amount of tracer emptying after administration of cholecystokinin. |
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APPENDICITIS
Findings on ultrasonography |
diameter of > 6 mm, noncompressibility, lack of peristalsis, and periappendiceal fluid collection.
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MIDGUT VOLVULUS
CT Findings |
characteristic whirlpool sign, i.e., bowel loops and superior mesenteric vein wrapping around the superior mesenteric artery
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PANCREATITIS
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CT:
May be equivocal if done 48 hours prior to onset of symptoms. Characteristic findings include bulky, swollen pancreas with surrounding edema; localized fluid collections; abscesses; pancreatic ductal dilatation; and associated complications. There are various scoring systems to grade severity of disease based on CT findings. |
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ESOPHAGEAL CANCER
What modality is recommended for staging? What modality is becoming popular for this purpose? |
CT and endoscopic US
PET (more accurate staging cuz greater propensity to diagnose metastasis) |
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CECAL VOLVULUS
Initial test? Confirm? CT findings? |
Plain x-ray: Findings include displaced cecum, small and large bowel obstruction up to the point of torsion, and paucity of gas in the distal colon.
Hypaque enema (single contrast) may confirm the diagnosis and may also lead to reduction of the volved cecum. CT scan reveals the characteristic “swirl sign” |
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SIGMOID VOLVULUS
|
Abdominal x-ray is usually diagnostic. It classically reveals double loop (pelvic colon) obstruction with varying degrees of proximal small bowel obstruction. The twisted dilated loop is located in the right side of the abdomen and forms a central double wall that converges in the right lower quadrant called the “coffee bean” sign.
Single-contrast barium enema is helpful in diagnosis in equivocal cases and may result in decompression and reduction. CT scan is useful for delineating complications like vascular ischemia. |
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GALLSTONE DISEASE AND CHOLECYSTITIS
Initial? Limitations? |
Ultrasound: demonstrates multiple echogenic (bright) foci within a distended gallbladder with dense distal posterior acoustic dark shadowing (flashlight sign) suggestive of gallstones. Always look for associated dilatation and calculi within the biliary ductal system.
Limited exam with big body habitus, inadequate distention, or overlying bowel gas. Characteristic findings include thickened gallbladder wall, pericholecystic fluid, positive ultrasound, Murphy’s sign |
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Hepatobiliary iminodiacetic acid (HIDA) scan (cholescintigraphy)
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used when ultrasound is unavailable.
Tc-labeled iminodiacetic acid is injected via an IV catheter followed by sequential imaging. Hepatic uptake occurs within the first 15 minutes and the tracer reaches the duodenum in 1 hour. Obstructing gallstones are characterized by lack of uptake of the tracer in the gallbladder and the cystic duct. Gallbladder contraction can be assessed by amount of tracer emptying after administration of cholecystokinin. |
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PANCREATITIS
|
CT:
May be equivocal if done 48 hours prior to onset of symptoms. Characteristic findings include bulky, swollen pancreas with surrounding edema; localized fluid collections; abscesses; pancreatic ductal dilatation; and associated complications. There are various scoring systems to grade severity of disease based on CT findings. |
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ESOPHAGEAL CANCER
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What modality is recommended for staging?
What modality is becoming popular for this purpose? CT and endoscopic US PET (more accurate staging cuz greater propensity to diagnose metastasis) |
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INDICATIONS FOR KUB
ADVANGATES? DISADVANTAGES? |
Kidney stones
Free air indicating perforated viscera. Free air may be visualized under the domes of the diaphragm in an upright view. In sick patients, lateral decubitus view is helpful. Abnormal calcifications Renal agenesis Ascites: Look for obliteration of peritoneal fat pads, displacement of bowel loops Bowel obstruction Foreign bodies Skeletal pathologies Quick Inexpensive Noninvasive Easy availability Renal outline may be obscured by bowel gas. Radiation exposure No functional information Retained barium from other procedures may interfere with visualization. |
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What four things do you look for in a Renal US?
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1. Kidney size: Large variation in size based on age. Length ranges from 10-14 cm and breadth 3-5 cm.
2. Location: Normal location is retroperitoneal, paraspinal, behind the liver on the right and spleen on the left. Right kidney is lower than the left due to the liver. 3. Renal outline: Should normally be smooth. Irregular outline may be from masses or scars. 4. Corticomedullary differentiation: Cortex appears hypoechoic (bright) relative to the medulla, which is hypoechoic. In a normal kidney, this differentiation is well maintained. |
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Indications for renal US
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1. Hydronephrosis: Appears as calyceal splitting. In cases with distal obstruction, proximal end of dilated ureter may be seen.
2. Calculi: Appear as echogenic (bright) structures with distal acoustic shadowing. 3. Cysts: US is extremely useful for delineating cystic vs. solid lesions and defining cyst characteristics 4. Renal masses 5. US guidance may be used for kidney biopsy, e.g., in medical renal disease 6. Renal artery stenosis: Combined with Doppler, US is the screening modality of choice for renal artery stenosis 7. Enlarged/ shrunken kidneys: Enlarged kidneys may be seen in Amyloidosis, Multiple myeloma, Diabetes mellitus. Atrophic kidneys may be post obstructive or post infective. |
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three common reasons for an ABD CT
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1. Renal stone disease (painful hematuria): Noncontrast CT is becoming the gold standard for detection of renal calculi. It is highly sensitive and specific in picking up even small calculi (2 mm). Remember to look for proximal signs of obstruction.
2. Renal/bladder masses (painless hematuria): CT can delineate exact extent, characteristics, vascular involvement, lymph node, presence or absence of calcifi cation. Note: For bladder masses, cystoscopy may be used for direct visualization of the mass and obtaining biopsy or cauterization of active bleeding sites. 3. Trauma: CT is helpful in estimating the degree of trauma. It also provides functional information and is helpful in staging, which is used for prognosis |
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Describing Fx
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1. Describe fracture type (displaced, greenstick, comminuted, plastic deformity)
2. Determine the location of the fracture (proximal, middle, and distal) 3. Check for intra-articular extension of the fracture. 4. Look for surrounding soft tissue swelling and/or foreign body. “This is a right wrist x-ray of Mr. Smith. There is a comminuted fracture of the distal radius with intra-articular extension. Associated soft tissue swelling. No additional fractures identified.” |
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Jefferson Fx?
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burst fx of C1
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Dens (Odentoid) Fx
Type I Type II Type III |
Type I: Fracture involving the tip of the dens
Type II: Transverse fracture involving the base of the dens (MC) Type III: Fracture extending into the body of C2 |
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Hangman's Fx
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Fracture of C2 through the bilateral pars interarticularis caused by hyperext injx
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Clay Shoveler's Fx
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Fx of posterior spinous process of C6, C7, T1, T2 from hyperFLEXION injx. C7 is MC
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XR of Ankylosing Spondylitis
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Lateral plain film: Smooth symmetric syndesmophytes referred to as “bamboo spine”
AP plain film: Fusion of the sacroiliac joints |
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MC location of clavicular fx
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Middle 1/3
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Colle's Fx
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MC FX of FOREARM
Transverse, often communicated fracture of the distal radius with dorsal angulation of the distal fracture fragment Associated fracture of the ulnar styloid process sometimes seen |
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Scaphoid Fx
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MC FX of carpal bones
AP, lateral, and scaphoid views: Most are transverse fractures through the long axis of the bone |
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Boxer fracture?
Bennett fracture? Rolando fracture? |
Fracture of the distal fifth metacarpal.
Linear fracture at the base of the first metacarpal with intra-articular extension. Same as Bennett fracture except the fracture is comminuted. |
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Swan Neck deformity?
Boutonniere deformity? |
ext of PIP flex of DIP
flex of PIP ext of DIP |
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Sausage digits
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Psoriatic Arthritis
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If an x-ray is negative at the time of an injury, a repeat x-ray in ____ days could be obtained since the initial fracture may be occult.
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7-10d
A fracture becomes more visible a week after the injury due to subsequent decalcification after the initial injury. |
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What imaging is needed for Hip Dislocations?
|
CT scan should be performed for all hip dislocations to look for bony
fragments or femoral/acetabular fractures, which occurs in 10% of all hip dislocations . |
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Osteosarcoma
MC in what age group? Findings? |
MC in 15-25yo
"sunburst appearance" and Codman's triangle |
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The most common
fracture of the proximal tibia is the |
tibial plateau fracture.
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Most common fracture of the ankle is the ______ or _________
|
medial or lateral malleolus fracture
|
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What is a bimalleolar fracture?
What is a trimalleolar fracture? |
involves both the medial and lateral malleolus
involves the posterior, medial, and lateral malleolus |
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Lisfranc Fracture/Dislocation
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Fracture and lateral dislocation of the second, third, fourth, and fifth metatarsal. Up to 20% of Lisfranc fractures/dislocations are missed on x-rays.
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Salter Harris Type I
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Fx thru physis, usually seen in kids <5yo
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Salter Harris Type II
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Fx thru physis AND metaphysis, most commonly distal radius and tibia
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Salter Harris Type III
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Fx thru physis AND epiphysis, most commonly seen in knees and ankles
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Salter Harris Type IV
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Fx thru physis AND metaphysis AND epiphysis, commonly seen at lateral condyle of humerus
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Salter Harris Type V
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Crush injx of the physis
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