Inservice

Radiology Inservice Thoracic Section

177.

A. Pulmonary artery sarcoma: The majority of patients with pulmonary artery sarcomas present between the ages of 45-55, and the tumor is found more commonly in women (2:1). Patients complain of dyspnea, chest pain, and cough. Prognosis is very poor, with an average of 12 month survival after diagnosis. The tumor most commonly arises from the intima and appears as an intralumenal filling defect. Direct transmural spread into the adjacent lung, bronchial wall, or lymph nodes occurs in about 50% of cases. On CT and angiography, the mass may appear similar to thrombus, however, contrast enhancement can be seen on post gadolinium MR images {Radiographics 1997; 17: 145-153].

B. Takayasu's

C. Chronic pulmonary emboli: Vascular occlusion of small arteries supplying secondary pulmonary lobules produces inhomogeneous attenuation (regional hypoperfusion and decreased lung attenuation) of the lung parenchyma or a "mosaic" pattern which may be seen in association with chronic pulmonary embolism [AJR, Nov95, p.1082-83; AJR, Dec 95, p.1361]. Mosaic oligemia may need to be distinguished from other causes of localized decreased lung attenuation such as regional air trapping- this can be accomplished with the use of expiratory images. Wedge shaped areas of peripheral infarction may also be identified. Other findings on CT include enlargement of the main pulmonary arteries (secondary pulmonary arterial hypertension), pulmonary artery filling defects, variation in size of the segmental vessels, and pulmonary artery calcifications. Helical CT is superior to conventional angiography in the detection of mural thrombi associated with chronic pulmonary embolism.

D. Atrial septal defect

E. Eisenmenger's syndrome

178.

A. Penetrating aortic ulcer

B. Aortic dissection

C. Mycotic aneurysm

D. Giant cell aortitis

E. Aortic laceration

179.

180. Williams' syndrome: D. Patients affected with Williams' syndrome have a characteristic elfin facies and are also mentally retarded. Cardiac findings included supravalvular aortic stenosis and pulmonic stenosis. Osseous findings include osteosclerosis, dense broad zones of provisional calcification, metaphyseal lucent bands, dense vertebral endplates, and metastatic calcification due to idiopathic hypercalcemia. Spontaneous resolution of the bony changes is seen in most patients after 1 year of age. Other findings include bladder and colonic diverticuli.

181. Noonan's syndrome: B. Patients with Noonan's syndrome (mental retardation, web neck, and short stature) have an increased incidence of pulmonic stenosis- found in up to 30% of cases.

182. Holt-Oram syndrome: A. Holt-Oram is an autosomal dominant disorder that affects females more than males. The disorder is associated with atrial septal defects (most commonly a secundum ASD), but patients may also have ventricular septal defects or a persistent left SVC. Skeletal lesions in Holt-Oram include aplasia/hypoplasia of the radial structures of the upper extremity (thumb, 1st metacarpal, carpal bones, radius), hypoplastia mof the clavicle, and cervical scoliosis. Symmetry of the lesions is the rule, although the left side may be more severely affected.

183. Large aorta and left atrium: C. In patent ductus arteriosus blood is shunted from the aorta to the left pulmonary artery. The left atrium and left ventricule handle an increased volume of blood, but the right ventricle is not involved. Radiographic findings in patent ductus arteruiosus include shunt vascularity, LAE, and LVE coupled with enlargement of the transverse portion of the thoracic aorta. Patients with PDA's tend to preferentially shunt blood to the right lung so the pulmonary vascularity may appear asymmetric. PDA accounts for about 10% of congenital heart disease and females are affected more than males (4:1). The condition is associated with Down's syndrome, rubella syndrome, and prematurity. On exam there is a widened pulse pressure (due to diastolic siphon of blood into the pulmonary circulation). Associated cardiac anomalies include: VSD, coarctation of the aorta or hypoplastic aortic arch, and pulmonic stenosis. If long standing, pulmonary arterial hypertension may develop and result in shunt reversal.

184. Normal aorta, large right atrium, and large right ventricle

185. Pulmonary edema and normal heart size

186. Dilated cardiomyopathy: D.

187. Hypertrophic cardiomyopathy: A.

188. Restrictive cardiomyopathy: B.

[MRI Clin North Am, May 1996, p.269-286]

Cardiomyopathies Can be classified as either hypertrophic, dilated, or restrictive.

Hypertrophic Cardiomyopathy: Hypertrophic cardiomyopathy is probably a genetic disorder characterized by inappropriate left ventricular hypertrophy often with left ventricular outflow tract (LVOT) obstruction. Histologically there is muscular hyperplasia with myocardial cellular disorganization, myocardial fiber disarray, and fibrosis. The histologic changes result in an increased risk for ventricular dysrhythmia which is a common cause of mortality in these patients. Two distinct sub-types of hypertrophic cardiomyopathy are recognized- asymmetric septal hypertrophy (ASH), and apical hypertrophy.

a) Asymmetric septal hypertrophy: ASH is the more common hypertrophic cardiomyopathy and is characterized by a disproportionate thickening of the interventricular septum (as compared to the posterolateral wall or apex) which results in a sub-valvular left ventricular outflow tract obstruction. The anterolateral wall is also commonly involved. The disorder is characterized by decreased systolic thickening of the septum, abnormal anterior motion of the anterior leaflet of the mitral valve during systole, and mitral regurge. The degree of LVOT obstruction is exacerbated by the systolic anterior motion of the mitral valve. On spin echo MR images findings include asymmetric thickening of the ventricular septum and regions of decrease signal intensity (which may represent areas of fibrosis). Cine MR imaging can demonstrate the lack of change in septal thickness between systole and diastole, regurgitant abnormalities associated with septal hypertrophy (due to paradoxical anterior motion of the anterior mitral valve leaflet during systole which produces mitral regurgitation), and delayed septal enhancement following the administration of gadolinium.

b) Apical hypertrophy: In this disorder, there is marked myocardial thickening to the left ventricular apex. The disorder is usually clinically benign and frequently associated with systemic hypertension in older men. A characteristic EKG change associated with the disorder is giant negative T-waves. There may be a genetic basis for the disorder as it is encountered much more frequently in Asian populations, but rare in Western countries.

Dilated Cardiomyopathy: Dilated cardiomyopathy is a pathophysiologic classification characterized by ventricular dilatation and systolic dysfunction with decreased ejection fraction. Dilated cardiomyopathy is the most common of the three forms of cardiomyopathy. Although it may involve the right ventricle, the left ventricle is usually more severely involved and hence, more dilated (although four chamber dilatation is not uncommon).

Restrictive Cardiomyopathy: Restrictive cardiomyopathy is also a pathophysiologic classification characterized by impairment of ventricular diastolic filling. Restrictive cardiomyopathies produce decreased left ventricular compliance which results in resistance to left atrial emptying and poor diastolic filling. Hemodynamic and clinical features of this disorder are difficult to distinguish from constrictive pericarditis. Etiologies such as sarcoid or amyloid produce increased left ventricular thickness associated with heterogeneous signal characteristics on MR imaging. Hemochromotosis also produces a restrictive cardiomyopathy which is characterized by signal loss of the myocardium secondary to iron deposition. The pericardium should be of normal thickness in patients with restrictive cardiomyopathy.

189. In a spin echo sequence, blood that appears white has receivced both 90 degree and 180 degree pulses?

190. Each image in a multislice sequence is ECG-gated to a different time after the R-wave? T.

191. Patients with recently manufactured heart valves are safely imaged in a 1.5 T magnet? T.

192. Cine-phase imaging allows measurement of blood flow velocity?

193. The repetition time with cardiac gating is equal to the heart rate? T. Gating to the ECG enhances image resolution as a result of decreased blurring. The TR value is determined by the heart rate (e.g., a patient with a heart rate of 60 would have a TR of 1000 msec).

Concerning total anomalous pulmonary venous return:

194. An ASD is part of the complex of TAPVR? T

195. Infradiaphragmatic drainage into the portal vein produces both cardiomegaly and pulmonary edema? T

196. CXR findings of the supradiaphragmatic form of TAPVR simulate those of hypoplastic left heart syndrome?

197. Anomalous connection to the portal vein passes through the aortic hiatus of the diaphragm? F

198. The most common site of anamolous connection in TAPVR is the left inominate vein? T

Total Anomalous Pulmonary Venous Return (TAPVR): All pulmonary veins from both lungs drain into the systemic venous circulation (ie: to the right atrium). TAPVR results from embryologic failure of the common pulmonary vein to join the posterior wall of the left atrium. A right to left communication (such as an ASD, VSD, PDA, or combination of lesions) is necessary for survival. The most common type of communication is an ASD of the sinus venosus type. Patients present with cyanosis and congestive heart failure at birth which improves as the pulmonary vascular resistance decreases. There are 4 types of anomalous pulmonary venous return:

1- Supracardiac: This is the most common variety accounting for 50% of cases. The pulmonary veins drain to a supracardiac vein (left vertical vein [or left SVC] to left inominant (brachiocephalic) connection due to persistence of left anterior cardinal vein. (Note: The left SVC normally drains into the coronary sinus, however, this connection is lost in patients with TAPVR). A "Snowman" configuration is produced on the CXR where the head represents the dilated SVC and engorged left vertical vein and the body is due to right atrial and right ventricular enlargement. On the lateral exam the left SVC is seen anterior to the trachea and produces a pretracheal density.

2- Cardiac: (30%)

A. Coronary sinus (Site of confluence of coronary veins): Pulmonary veins connect to the coronary sinus which dilates.

B. Right Atrium: Pulmonary veins empty directly into the right atrium posteriorly.

3- Infracardiac: (12%) There is a persistent communication with the umbilical-vitelline venous system. The pulmonary veins join to form a large single vein which descends through the esophageal hiatus to join the portal vein, hepatic vein, or IVC. This condition is almost always associated with obstruction of the pulm. venous drainage due to the long course and high pressures. Patients are dyspnic and severely cyanotic at birth, and the cyanotic episodes are exacerbated by feeding (the bolus compresses the pulmonary vein near the distal esophagus). Death usually occurs within a few days. Infradiaphragmatic TAPVR is associated with Asplenia syndrome (80%). On CXR there is severe pulmonary edema with a normal sized or enlarged heart. Pleural effusions may be seen. Severe obstruction will result in persistent fetal circulation with R->L shunting and therefore classic interstitial edema may not be seen.

4- Combination of the above.

- X-ray:

On CXR in TAPVR there will be shunt vascularity, cardiomegaly (esp. right heart- right atrial and right ventricular), a prominent pulmonary artery segment, and no left atrial enlargement.

Concerning coronary artery disease:

199. Hemorrhage into a plaque is the most common cause for myocardial infarction? T

200. Cocainne causes coronary vasoconstriction? T

201. Mitral insufficiency is usually do to chordae tendineae rupture? T

202. Stenoses in the diagonal arteries affects perfusion in the septum? F. Diagonal branches arise from the left anterior descending arteyr and supply the anterolateral wall.

Concerning cardiac masses:

203. Left atrial myxomas usually originate in the appendage? F. Left atrial myxomas are benign neoplasms which arise most commonly from the inter-atrial septum in the region of the fossa ovalis- extending into the left atrium (75%) more commonly than the right. Ventricular myxomas are uncommon. Myxomas may rarely be familial, multiple, or occur as part of a complex consisting of Cushing's syndrome, skin lesions, and myxoid fibroadenomas of the breast. [MRI Clin North Am, May 1996, p.245-47]

204. Rhabdomyoma is associated with tuberous sclerosis? T. Rhabdomyoma is the most common primary pediatric cardiac tumor. It is a hamartomatous lesion and is associated with tuberous sclerosis in 50% of patients. The tumors are frequently multiple and intramural (purely intramural lesions may not be identified on MR imaging, although they may be seen following contrast enhancement).

205. The most common pericardial metastasis is a malignant melanoma? F.

206. Lipomatous hypertrophy of the interatrial septum is associated with supraventricular arrhythmias? T. The condition is not a true neoplasm (unlike a lipoma), but rather a focal collection of mature adipose tissue. It is found in obese, female, and elderly patients. There may be an association with cardiac arrhythmias.

207. Pericardial mesothelioma is associated with asbestos exposure? T.

Concerning valvular heart disease:

208. The right pulmonary artery dilates in pulmonary stenosis? F. In cases of severe pulmonic stensosi, post-stenotic dilatation of the main or left pulmonary arteries may be seen. Initially, there is right ventricular hypertrophy, and later enlargement and failure.

209. A domed aortic valve is a sign of aortic regurge?

210. Both the mitral annulus and leaflets calcify in most patients with rheumatic heart disease?

211. In Marfan's syndrome, approximately 50% of patients have mitral valve prolapse?

Concerning pericardial disease:

212. In constrictive pericarditis, the CXR shows pulmonary edema?

213. Tuberculous pericarditis usually develops by direct extension from infected mediastinal lymph nodes?

214. In constrictive pericarditis, the fibrotic pericardium impedes systolic contraction of the ventricles? F. Constrictive pericarditis results in impaired diastolic filling of the heart due to fibrosis and thickening of the pericardium- pressures between the atria and ventricles equilibrate.

215. Acute hemorrhagic pericardial effusion has high signal intensity on T1-weighted images?

216.

217.

222. Tuberculosus: A.

223. Pulmonary sling: D. In this condition the left pulmonary artery is absent due to failure of development or obliteration of the pulmonary branch of the left 6th aortic arch. An aberrant left pulmonary artery then arises from the right pulmonary artery and runs posterior to the trachea (over the right mainstem bronchus) and anterior to the esophagus to get to the left lung.

224. Relapsing polychondritis: C. Relapsing polychondiritis is a rare, systemic inflammatory disease of unknown etiology which involves the cartilage of the nose, ears (85%), upper respiratory tract (50-70%), and joints. Involvement of the respiratory tract can affect all cartilage containing portions of the trachea and bronchi and is associated with a poor prognosis (mortality approaches 50%). Nearly 25% of patients will have an associated collagen vascular disease. The disorder is characterized by recurrent episodes of cartilagenous inflammation which eventually leads to fibrous replacement of the damaged cartilage and fixed narrowing of the trachea. Rarely, flaccidity may result. Treatment involves dilatation and stenting. Radiographically, diffuse narrowing of the trachea and mainstem bronchi may be appreciated in association with mild, diffuse wall thickening (both anterior and posterior walls are affected). Focal stenoses may also occur. [J Thorac Imag 1995, 10: p.236; ACR Syllabus #40: p.270]

225. Papilloma: E. (Assuming that the question is regarding "pulmonary" spread, and not the more common airway lesions). In papillomas, an airway film may show multiple small tracheal nodules. Distal airway lesions may obstruct and can result in atelectasis. Pulmonary spread is characterized by multiple well defined nodules which frequently cavitate. The cavities usually have thin walls (2-3 mm thick) and may contain air-fluid levels.

226. Carcinoid:

227. Hamartoma: