BodyCT Flashcards
A burst fracture of the C1 ring?
jefferson fracture
any break in the bony ring of a vertebra that occurs on a slice that shows the __________ _______ is a spondylolysis until proved otherwise?
basivertebral plexus
Helps distinguish myositis ossificans from parosteal osteosarcoma?
Parosteal sarcoma demonstrates central clumps of calcification and myositis ossificans has peripheral ossification/calcification.
Define disk bulge, sequestered or free fragment?
Disk bulges can be diffuse, broad based, or focal but are attached to the disk. Sequestered or free fragments occur when disk material migrate from parent disk.
Distinguishing a free fragment from a Tarlov cyst or conjoined nerve root?
A free fragment is hyperdense to thecal sac and Tarlov cyts and conjoined nerve roots are isodense to thecal sac.
Lateral disk protrusion affects what nerve root?
A nerve rooth that has already exited the neuroforamen at a more cephalad level.
Congenital causes of spinal stenosis?
Achondroplasia, Morquio’s disease, idiopathic spinal stenosis
Acquired spinal stenosis causes?
Degenerative disk disease, post-traumatic stenosis, postsurgical stenosis, Paget’s disease, calcification of posterior longitudinal ligament.
Anatomic classification of spinal stenosis?
Central canal stenosis, neuroforaminal stenosis, lateral recess stenosis.
Most useful CT criteria for diagnosing central canal stenosis?
Obliteration of epidural fat, flattening of thecal sac.
Pars interarticularis defect?
Spondylolysis
Anterior displacement of a cephalad vertebral body with respect to a caudad vertebral body?
Spondylolisthesis. Grade I (<25%), II (25-50%), III (50-75%), IV (75-100%).
Most common site for coalition?
Calcaneonavicular joint.
Finding causing the greatest concern for metastatic bone disease or multiple myeloma involvement?
A permeative process.
Spinal hemangioma CT features?
vertical trabecular thickening, may contain fat, may see phleboliths.
Schmorl’s node?
Herniation of disk material through end plate of vertebral body.
Tarlov cysts?
Nerve sheath dilatations of fluid density at CT, when large enough can cause bone erosion, particulary within the sacrum.
Paget’s disease on CT?
Purely lytic or sclerotic or mixed. Bone overgrowth, Cortical thickening, disorganized trabecular thickening, in pelvis-thickenign of iliopectineal or ilioischial lines.
Fibrous dysplasia?
Congenital disorder of bone, fibrous tissue, chondral tissue, and even cysts within bone. Non-aggressive appearance.
Common right-sided anomalous pulmonary venous return insertions?
SVC azygos vein, IVC, Right atrium.
Common left-sided anomalous pulmonary venous return insertions?
Left brachiocephalic vein, persistent left SVC, Coronary sinus.
CT features that suggest lung cancer?
Irregular or spiculated margine, Lobulated contour, Air bronchograms or cysts within nodule, Nodular cavitation, > 2 cm.
Lung hamartoma CT features?
Smooth, rounded, or lobulated contour. Fat 60% Fat and calcification 30% Diffuse calcification 10%–“popcorn”.
4 findings of rounded atelectasis?
- Ipsilateral pleural thickening or effusion. 2. Contact between lung lesion and pleural surface. 3. “comet tail” sign. 4. Volume loss of lobe involved.
Air-crescent sign?
Lung mass capped by a crescent of air. Most typical of mycetoma (fungus ball). Fungus ball (Aspergillus) forms in preexisting cyst or cavity.
Lung abscess CT features?
Necrosis or cavitation within area of pneumonia or dense consolidation.
Satellite nodules and galaxy sign?
Granulomatous lesions with smaller nearby nodules–satellite. In sarcoidosis, galaxy sign is a larger nodule with nearby grouped smaller nodules
Benign pulmonary nodule calcification patterns?
Diffuse (granuloma), Central “bullseye” (histoplasmosis), Popcorn (hamartoma), Concentric “target” (histoplasmosis).
Benign pulmonary nodule doubling times?
< 1 month, or > 16 months.
What increase in diameter equals a doubling of volume?
26% increase (10 mm to 12.6 mm)
Differential, multiple large pulmonary nodules?
Metastases Lymphoma Bronchogenic carcinoma Bacterial, fungal, and sometimes viral infections Granulomatous disease Sarcoidosis Wegener’s granulomatosis Rheumatoid lung Amyloidosis Septic emboli
Pulmonary metastasis characteristics?
Typically round and well-defined. Cavitation and calcification can be seen.
Signet ring sign?
Bronchiectasis. Cross section of pulmonary artery branch adjacent to dilated, ring-shaped bronchus.Bronchus diameter exceeds adjacent artery’s
Bronchiectasis patterns in cystic fibrosis and allergic bronchopulmonary aspergillosis?
CF-bilateral, upper lobes, most severe at parahilar lungs. ABPA-central bronchiectasis.
Causes of interlobular septal thickening as predominant finding at HRCT?
- Lymphatic spread of carcinoma. 2. Interstitial pulmonary edema. 3. Alveolar proteinosis. 4. Sarcoidosis.
Common causes of fibrosis and honeycombing as predominant HRCT findings?
IPF 65%, Collage vascular diseases (RA, scleroderma), Drug-related fibrosis, Asbestosis, End-stage hypersensitivity pneumonitis, End-stage sarcoidosis.
3 distributions of pulmonary nodules at HRCT?
Perilymphatic nodules (pleural surface, large vessels and bronchi, interlobular septa, centrilobular regions), Random nodules (miliary TB, hematogenous metastases), Centrilobular nodules (tree-in-bud–endobronchial TB, MAC/MAI, CF, bronchiectasis, bronchopneumonia).
CT features of pulmonary lymphangitic spread of carcinoma?
Interlobular septal thickening, Peribronchial interstitial thickening, Thickening of fissures, Lymph node enlargement, Patchy distribution.
CT features of pulmonary hematogenous spread of tumor?
Random distribution, Fissures and pleural surface involvement, Bilateral, Large nodules.
CT features of IPF (idiopathic pulmonary fibrosis–UIP is histology pattern)?
Intralobular interstitial thickening, Honeycombing, Traction bronchiectasis and bronchiolectasis, Subpleural, posterior, and basal lungs, Ground-glass opacity.
Nonspecific interstitial pneumonia (NIP, collagen vascular disease) CT features?
Ground-glass opacity, Posterior basal lungs-sparing immediate subpleural lung, Reticulation, traction bronchiectasis and bronchiolectasis, Honeycombing-rare.
Active sarcoidosis CT features?
Perilymphatic nodules, Patchy, upper lobe predominance, Hilar, mediastinal node enlargement, Ground-glass opacity (small granulomas).
HRCT findings in end-stage sarcoidosis?
Irregular septal thickening, Architectural distortion, Parahilar conglomerate masses, Honeycombing, Hilar and mediastinal node enlargement.
Pulmonary lymphangitic spread of carcinoma?
Interlobular septal thickening, Peribronchial interstitial thickening Patchy or unilteral distribution Lymph node enlargement.
Pulmonary hematogenous spread of tumor?
Random distribution, Involvement of fissures and pleural surfaces, Bilateral distribution, Large nodules.
Idiopathic pulmonary fibrosis CT features?
Intralobular thickening, Honeycombing, Traction bronchiectasis and bronchiolectasis, Predominant subpleural, posterior, basal lung regions, Ground-glass opacity.
Nonspecific interstitial pneumonia CT features?
Ground-glass opacity, Predominant posterior and basal lung, sparing the immediate subpleural lung, Reticulation, traction bronchiectasis and bonchiolectasis, Honeycombing.
Collagen vascular disease as lung disease?
Rheumatoid lung, scleroderma, and other collagen disease (UIP, NSIP, BOOP)
Active pulmonary sarcoidosis CT features?
Perilymphatic nodules, Patchy, Upperlobe predominance, Hilar, mediastinal nodes, Ground-glass opacity, small granulomas.
End-stage sarcoidosis?
Irregular septal thickening, Architetural distortion, Parahilar conglomerate, honeycombing, Hilar, mediastinal nodes.
Silicosis and Coal Worker’s pneumoconiosis?
Perilymphatic nodules, Symmetric distribution, Posterior lung predominance, Upper lobe predominance, Conglomerate masses, Hilar, mediastinal nodes (egg-shell calcification).
Pulmonary Tuberculosis CT features?
Endobronchial spread (centrilobular nodules, tree-in-bud, focal areas of consolidation, bronchial wall thickening or bronchiectasis, pathcy or focal), Miliary spread (random nodules, 1-5 mm, Usually diffuse).
Pulmonary alveolar proteinosis?
Filling of alveolar spaces with lipid-rich proteinaceous material, Patchy or geographic ground-glass opacity, smooth, interlobular septal thickening in ground-glass–“crazy paving””.
Hypersensitivity pneumonitis, subacute stage CT features?
Patchy or geographic ground-glass opacity, Poorly defined centrilobular nodules or ground-glass opacity, Mosaic perfusion, Air trapping.
Bronchiolitis obliterans organizing pneumonia, causes?
Idiopathic, infections, toxic exposures, drug reactions, autoimmune disease.
HRCT features of bronchiolitis obliterans organizing pneumonia?
Patchy or nodular consolidation, Patchy or nodular ground-glass opacity, Peripheral and peribronchial distribution.
Chronic eosinophilic pneumonia?
Filling of alveoli by mixed inflammatory infiltrate (eosinophils), similar to BOOP–patchy consolidation or ground-glass, peripheral distribution.
Histiocytosis (aka Langerhans histiocytosis or eosinophilic granuloma)?
Centrilobular nodules (may cavitate), Thin-walled, irregular lung cysts, Normal appearing intervening lung, Upper lobe predominance, Spares costophrenic angles.
Lymphangiomyomatosis?
Women of child bearing age, can occur in Tuberous sclerosis, too, Thin-walled, round lung cysts, Normal-appearing intervening lung, Lymph node enlargement, Diffuse distribution without sparing lung bases.
List 4 types of emphysema?
Centrilobular (upper lobes, smokers, most common form), Panlobular (less common, alpha1-antitrypsin, most severe at lung bases), Paraseptal (subpleural lung, adjacent to chest wall and mediastinum), Bullous (Large bullae, young men).
Split pleura sign?
Thickened visceral and parietal pleural layers are split apart and surround an empyema.
Extension of an empyema to involve the chest wall is termed?
empyema necessitatis.
Lung abscess versus empyema CT characteristics?
Abscess (poorly defined, irregular wall, spherical, multiple cavities, acute angles, vessels not displaced), Empyema (well defined, smooth, uniform wall, elliptical, split pleura, acute or obtus angles, vessels displaced).
CT features of a malignant effusion?
Nodular pleural thickening, pleural thickness > 1 cm, concentrically involves the pleura, encasing the lung, thickening of mediastinal pleura.
CT findings for chest wall invasion?
Extensive contact between tumor and chest wall (> 3cm or ratio > 0.7), Obtuse angles, Chest wall mass, Bone destruction
What passes through the aortic hiatus?
Aorta, azygos, hemiazygos, thoracic duct, intercostal arteries, splanchnic nerves.
What passes through the esophageal hiatus?
Esophagus, vagus nerve, small blood vessels.
Anterior mediastinal node groups?
Internal mammary nodes, Paracardiac nodes, Prevascular nodes.
Middle mediastinal node groups?
Pretracheal or paratracheal nodes, Aortopulmonary nodes, Subcarinal noes, Peribronchial nodes.
Posterior mediastinal node groups?
Paraesophageal nodes, Inferior pulmonary ligament nodes, Paravertebral nodes.
Upper limits of normal for subcarinal lymph node diameter?
1.5 cm
Egg-shell calcified mediastinal lymph node, differential?
Silicosis, Coal worker’s pneumoconiosis, Sarcoidosis, Tuberculosis.
Calcified mediastinal lymph node, differential?
Prior granulomatous disease (TB, histo, fungal, sarcoidosis), Silicosis, Coal worker’s pneumoconiosis, treated Hodgkin’s disease, Metastasis
Mediastinal lymph node enhancement?
Castleman’s disease, Angioimmunoblastic lymphadenopathy, Vascular metastases, TB, Sometimes sarcoidosis.
Left upper lobe cancers involve what mediastinal lymph node group?
Aortopulmonary window nodes
Lower lobe lung cancers involve what mediastinal lymph node group?
Subcarinal nodes
Resectability non-small cell lung cancer stages?
Stage IIIb-IV, contralateral lymph nodes are N3, unresectable
Sarcoidosis thoracic adenopathy features?
Symmetric hilar adenopathy, Lymphoma is typically asymmetrical.
Prevascular space tumors?
4Ts: thymoma, teratoma, thyroid tumor, terrible lymphoma. Other germ-cell tumors, parathyroid masses, lymphangioma
Castleman’s disease
aka angiofollicular lymph node hyperplasia Focal form (Enhancing hilar or mediastinal lymph nodes) Diffuse form (Enhancing mediastinal, hilar, axillary, abdominal, and inguinal node)
CT features of thymoma?
Prevascular or paracardiac location, Typically unilateral, Calcification or cystic degeneration can be present
Thymic masses?
Thymoma, thymic carcinoma, thymic carcinoid tumor, thymolipoma, thymic cyst thymic hyperplasia and rebound (after cessation of chemotherapy)
Three main categories of germ-cell tumors?
- Teratoma and dermoid cyst, 2. Seminoma (radiosensitive), 3. Non-seminomatous germ-cell tumors (poor prognosis: choriocarcinoma, endodermal sinus tumor, mixed tumors).
Teratoma versus dermoid cyst?
Teratoma contains ecto-, meso-, and endodermal origins (can be cystic, contain fat, have fat-fluid level, or calcify). Can be mature or immature (malignant). Dermoid cyst primarily from epidermal tissue.
Lymphangioma types?
Simple–small, thin-walled with connective tissue. Cavernous–dilated lymphatic channels. Cystic–hygromas, single or multiple cystic masses filled with serous or milky fluid.
Saber-sheath trachea features?
Narrowed lateral dimension of intrathoracic trachea. COPD, repeated trauma from coughing
Concentric tracheal narrowing causes?
Intubation, Polychondritis, Wegener’s granulomatosis, Amyloidosis, Tracheobronchopathia osteochondroplastica
Bronchogenic and esophageal duplication cyst features?
Anomalous budding of foregut. Most commonly within subcarinal space. Esophageal duplication cyst indistinguishable from bronchogenic, except they always contact the esophagus
Paravertebral neurogenic tumor divisions?
- Peripheral nerve or nerve sheath (neurofibroma, neurilemmoma–young adults). 2. Sympathetic ganglia (ganglioneuroma, neuroblastoma–children). 3. Paraganglionic cells (pheochromocytoma, chemodectoma).
Most common cause of posterior mediastinal mass in patients with neurofibromatosis?
Meningocele
Granulomatous mediastinitis causes?
Histoplasmosis, TB, Sarcoidosis, Chronic mediastinal lymph node enlargement with fibrosis. Calcification of lymph nodes common
Sclerosing mediastinitis versus granulomatous mediastinitis
Similar but no calcification with sclerosing mediastinitis.
Pericardial cyst features?
60% anterior right cardiophrenic angle, 30% left cardiophrenic angle, 10% occur higher in mediastinum.
Morgagni hernia features?
Anteromedial diphragmatic foramen of Morgagni. Cardiophrenic angle mass, 90% occur on right. Usually contains liver or omentum.