Radiology Flashcards
When is head CT with contrast an appropriate test? (2)
1.Evaluating for AV (arteriovenous) malformations 2. Evaluating for primary/metastatic tumors
When is an abdominal CT the best initial test?
Evaluating retroperitoneal structures (pancreas, nodal metastasis from colon/ prostate/ testicular/ renal cancer)
When is high resolution CT scan of the chest the test of choice? (2)
- Evaluating for parenchymal lung disease (interstitial fibrosis) 2. Evaluating bony structure
What is the major contraindicator for a CT or MRI with contrast?
Renal failure (creatinine > 1.5)
What should be avoided when performing an CT to a pt with multiple myeloma?
IV contrast
Why should you avoid contrast with an MRI of a renal disease pt?
Can result in nephrogenic systemic fibrosis
What medication should be discontinued before CT scan with IV contrast and not restarted until 48 hours after the scan when renal failure has been ruled out?
Metformin
When is an MRI the best diagnostic test? (10)
- Demyelinating disease (multiple sclerosis, dementia) 2. Posterior fossa 3. Base of skull 4. Orbit 5. Brain Tumors (acoustic neuromas, pituitary tumor, small intraparenchymal tumor) 6. Bone Tumors 7. Bone and soft tissue infections 8. Joint spaces 9. Aseptic necrosis of femoral head 10. Diseases of spinal cord and spinal column (herniated disc, spinal tumor, degenerative disc disease)
When is the HIDA (hepatobiliary) scan useful? (3)
- Evaluating biliary obstruction vs. acute cholecystitis 2. Evaluating for biliary leaks postoperatively 3. Evaluating for congenital abnormalities of biliary tract (biliary atresia)
When is a bone scan useful? (4)
- Metastatic bone lesions 2. Evaluating delayed fractures 3. Evaluating osteomyelitis 4. A vascular necrosis of the femoral head
When is an adrenal scan the test of choice?
Localizing a pheochromocytoma (when MRI/CT nondiagnostic
When is a V/Q (ventilation-perfusion) scan the test of choice?
Evaluating for pulmonary embolism (Normal scan rules out PE; indeterminate needs further eval with CT angiogram)
When should you not order a V/Q scan (for the evaluation of pulmonary embolism)? (2)
- COPD 2. Extensive lung disease
When is a gallium scan the test of choice? (3)
- Localizing abscesses 2. Staging lymphomas 3. Melanomas
When is an ultrasound the best initial test? (4)
- Evaluating gallbladder for stones (pt with RUQ pain) 2. Assessing uterus, adnexa, ovaries (except cervical cancer) 3. Evaluate prostate and aids in obtaining biopsy 4. Evaluate for deep venous thrombosis (DVT)
What are likely causes of lyric lesions on a x-ray film of the bones? (3)
- Multiple myeloma 2. Primary bone tumor 3. Metastasis (lung, renal, thyroid, breast)
What are likely causes of blastic bone lesion on bone x-ray? (3)
- Metastasis (breast, prostate, lymphoma) 2. Paget’s disease 3. Medulloblastoma in kid
What are likely causes of large mediastinum on chest x-ray? (2)
- Aortic aneurysm 2. Lymphadenopathy
What are likely causes of lung infiltrated with effusion on chest x-ray? (4)
- Staphylococcus pneumoniae 2. Streptococcus pneumoniae 3. Lung infarct 4. Tuberculosis
What are likely causes of small bowel obstruction on abdominal/pelvic radiography? (5)
- Adhesions 2. Hernia 3. Intussusception in kid 4. Gallstone ileus 5. Carcinoma