11 The Mediastinum, Including

the Pericardium

DR MUHAMMAD BIN ZULFIQARPGR III FCPS Services institute of Medical

Sciences/ Services Hospital LahoreGRAINGER & ALLISON’S DIAGNOSTIC RADIOLOGY

• FIGURE 11-1 Value of multiplanar reformations. A 45-year-old woman ■with dyspnoea: (A) frontal radiograph and (B) oesophogram demonstrate displacement of the trachea and oesophagus to the right, by a large mediastinal mass in the thoracic inlet. (C) Transaxial contrast medium-enhanced CT shows a large goitre arising from the left lobe of the thyroid. (D) Coronal reformat depicts the craniocaudal extent of the mass and its relationship with the adjacent structures.

• FIGURE 11-1 Value of multiplanar reformations. A 45-year-old woman with ■dyspnoea: (A) frontal radiograph and (B) oesophogram demonstrate displacement of the trachea and oesophagus to the right, by a large mediastinal mass in the thoracic inlet. (C) Transaxial contrast medium-enhanced CT shows a large goitre arising from the left lobe of the thyroid. (D) Coronal reformat depicts the craniocaudal extent of the mass and its relationship with the adjacent structures.

• FIGURE 11-2 Comparison of various techniques in assessment of goitre. A 90-year-old woman ■presents with swelling of her face and shortness of breath. (A) Transaxial and (B) sagittal reformatted images on contrast medium-enhanced CT imaging demonstrate a large intrathoracic goitre. Ultrasound evaluation of the neck using colour Doppler shows an enlarged left lobe of the thyroid with a mildly heterogeneous echogenicity. There are numerous tortuous venous collateral vessels surrounding the goitre, rendering safe fine-needle aspiration under ultrasound guidance impossible (C). 123I radionuclide imaging of the face and neck demonstrates iodine uptake of the goitre (D).

• FIGURE 11-2 Comparison of various techniques in assessment of goitre. A ■90-year-old woman presents with swelling of her face and shortness of breath. (A) Transaxial and (B) sagittal reformatted images on contrast medium-enhanced CT imaging demonstrate a large intrathoracic goitre. Ultrasound evaluation of the neck using colour Doppler shows an enlarged left lobe of the thyroid with a mildly heterogeneous echogenicity. There are numerous tortuous venous collateral vessels surrounding the goitre, rendering safe fine-needle aspiration under ultrasound guidance impossible (C). 123I radionuclide imaging of the face and neck demonstrates iodine uptake of the goitre (D).

• FIGURE 11-3 Role of scintigraphy in detecting parathyroid adenomas. A 66-year-old ■woman with hypercalcaemia. CT (not shown) did not reveal a parathyroid adenoma. 99mTc-sestamibi radionuclide imaging demonstrates uptake in both thyroid and parathyroid parenchyma in the 10-minute delayed image (left); however, at 2-hour delay, imaging (right) demonstrates persistent uptake in the right lobe of the thyroid gland, representing the parathyroid adenoma.

• FIGURE 11-4 Cystic thymoma. (A) Frontal ■and (B) lateral chest radiographs show an anterior mediastinal mass extending along the right heart border.

• FIGURE 11-4 Cystic thymoma. (A) Frontal and (B) ■lateral chest radiographs show an anterior mediastinal mass extending along the right heart border.

• FIGURE 11-4, Continued(C) Transaxial and (D) coronal reformatted CT images demonstrate the cystic and solid components of the mass. (E) T1- and (F) T2-weighted sequences reveal that the cystic portion has a low T1 and high T2 signal intensity and the solid portion is isointense to myocardium. T1-weighted, fat-saturated 3D acquisition (G) before and (H) after contrast media administration demonstrate heterogeneous enhancement of the solid component

• FIGURE 11-4, Continued(C) Transaxial and (D) coronal reformatted CT images demonstrate the cystic and solid components of the mass. (E) T1- and (F) T2-weighted sequences reveal that the cystic portion has a low T1 and high T2 signal intensity and the solid portion is isointense to myocardium. T1-weighted, fat-saturated 3D acquisition (G) before and (H) after contrast media administration demonstrate heterogeneous enhancement of the solid component

• FIGURE 11-4, Continued(C) Transaxial and (D) coronal reformatted CT images demonstrate the cystic and solid components of the mass. (E) T1- and (F) T2-weighted sequences reveal that the cystic portion has a low T1 and high T2 signal intensity and the solid portion is isointense to myocardium. T1-weighted, fat-saturated 3D acquisition (G) before and (H) after contrast media administration demonstrate heterogeneous enhancement of the solid component

• FIGURE 11-5 Invasive thymoma. A 74-year-old ■man with weight loss. (A) Chest radiograph displacement of the trachea and carina to the right and lobulation of the left pleura. CT demonstrates (B) multiple confluent pleural masses involving the medial and posterior pleura and (C) a mass arising from the thymus. A B C

• FIGURE 11-6 Thymic carcinoma. A 16-year-old man with history of ■weight loss and night sweats. Contrast medium-enhanced CT images show a heterogeneously enhancing anterior mediastinal mass arising from the right lobe of the thymus (A), with cystic (or necrotic) components. It extends inferiorly in the retrosternal space (B) and has no clear fat plane between it and the mediastinal structures (B). It was surgically excised and pathological examination revealed thymic carcinoma.

• FIGURE 11-7 Thymic carcinoid. A 58-year-old ■woman with palpitations. Contrast medium-enhanced CT images of the upper thorax (A–C) show an infiltrative soft-tissue mass arising from the anterior mediastinum, surrounding the mediastinal vasculature.

• FIGURE 11-7 Thymic carcinoid. A 58-year-old ■woman with palpitations. Contrast medium-enhanced CT images of the upper thorax (A–C) show an infiltrative soft-tissue mass arising from the anterior mediastinum, surrounding the mediastinal vasculature.

• FIGURE 11-8 Thymic hyperplasia with Graves’ disease ■(thyrotoxicosis). A 35-year-old woman with dysphagia, palpitations, tremors, exophthalmos and weight loss and elevated serum thyroid hormone. Contrast medium-enhanced CT demonstrates (A) enlarged thyroid and (B) thymus. Following treatment with I-131, (C) the thyroid gland and (D) thymus became much smaller.

• FIGURE 11-8 Thymic hyperplasia with Graves’ disease ■(thyrotoxicosis). A 35-year-old woman with dysphagia, palpitations, tremors, exophthalmos and weight loss and elevated serum thyroid hormone. Contrast medium-enhanced CT demonstrates (A) enlarged thyroid and (B) thymus. Following treatment with I-131, (C) the thyroid gland and (D) thymus became much smaller.

• FIGURE 11-9 Thymic cyst. Thoracic CT images (A) of a 64-■year-old woman with diabetes and weight loss show an incidental finding of a well-circumscribed, low-attenuation anterior mediastinal mass. MR demonstrates low T1 signal intensity (B) and high T2 signal intensity (C) without evidence of enhancement following intravenous contrast medium administration (D).

• FIGURE 11-9 Thymic cyst. Thoracic CT images (A) of a 64-year-■old woman with diabetes and weight loss show an incidental finding of a well-circumscribed, low-attenuation anterior mediastinal mass. MR demonstrates low T1 signal intensity (B) and high T2 signal intensity (C) without evidence of enhancement following intravenous contrast medium administration (D).

• FIGURE 11-10 Cystic teratoma. A 51-year-old man with prostate ■cancer was found to have an anterior mediastinal mass on chest radiograph (A, B). (C) CT shows a heterogeneous mass with areas of fat attenuation. (D) Gross pathological examination after surgical resection demonstrated sebaceous material and pieces of hair (not shown).

• FIGURE 11-10 Cystic teratoma. A 51-year-old man ■with prostate cancer was found to have an anterior mediastinal mass on chest radiograph (A, B). (C) CT shows a heterogeneous mass with areas of fat attenuation. (D) Gross pathological examination after surgical resection demonstrated sebaceous material and pieces of hair (not shown).

• FIGURE 11-11 Seminoma. A 19-year-old man ■with chest pain found to have a large anterior mediastinal mass on non-enhanced CT of the chest. The mass has a heterogeneous attenuation (A) and exerts mass effect upon the heart and airway (B).

• FIGURE 11-12 Metastatic choriocarcinoma. A 23-■year-old man presented with haemoptysis for 2 weeks. Chest CT demonstrates an anterior mediastinal mass of soft-tissue attenuation with slightly enhancing margins (A, B). (A) Mediastinal lymphadenopathy adjacent to the mass and (C) multiple pulmonary nodules dispersed throughout the lung are sites of metastases

• FIGURE 11-12 Metastatic choriocarcinoma. A 23-year-■old man presented with haemoptysis for 2 weeks. Chest CT demonstrates an anterior mediastinal mass of soft-tissue attenuation with slightly enhancing margins (A, B). (A) Mediastinal lymphadenopathy adjacent to the mass and (C) multiple pulmonary nodules dispersed throughout the lung are sites of metastases

• FIGURE 11-13 Large B-cell lymphoma. A 33-■year-old man found to have a lobular soft-tissue mass in the anterior mediastinum (A) extending to the right paratracheal and hilar regions (B).

• FIGURE 11-14 High-attenuation lymph nodes. ■Transaxial image of chest CT shows a calcified mediastinal lymphadenopathy. Such dystrophic calcification is common as a sequela of Histoplasma capsulatum infection; however, it can also be seen with metastatic lymphadenopathy of mucinous adenocarcinomas.

• FIGURE 11-15 Low-■attenuation lymph nodes. Transaxial contrast medium-enhanced CT image of the chest in a 51-year-old woman with fever and chest pain shows subcarinal lymphadenopathy with central low attenuation caused by necrosis (A). Axial CT image in lung window setting lower in the chest reveals numerous confluent nodules in bilateral lower lobes caused by acute Histoplasma capsulatum (B).

• FIGURE 11-16 Castleman’s ■disease. A 33-year-old woman with shortness of breath was further evaluated by contrast medium enhanced CT. Transaxial CT images show a normal thyroid (A), but narrowing and displacement of the trachea by a heterogeneously enhancing mediastinal mass located more inferiorly (B). The mass was surgically excised and pathological examination revealed hyaline vascular type of Castleman’s disease.

• FIGURE 11-17 Bronchogenic cyst. A 58-year-old man with ■hoarseness for several months. (A) Frontal and (B) lateral chest radiographs reveal a round middle mediastinal mass. (C) Coronal reformatted and (D) transaxial images of contrast medium-enhanced CT displayed in soft-tissue and lung-window settings, respectively, demonstrate a smooth-bordered, thin-walled mass of fluid attenuation located at the carina, closely associated with the right mainstem bronchus.

• FIGURE 11-17 Bronchogenic cyst. A 58-year-old man with ■hoarseness for several months. (A) Frontal and (B) lateral chest radiographs reveal a round middle mediastinal mass. (C) Coronal reformatted and (D) transaxial images of contrast medium-enhanced CT displayed in soft-tissue and lung-window settings, respectively, demonstrate a smooth-bordered, thin-walled mass of fluid attenuation located at the carina, closely associated with the right mainstem bronchus.

• FIGURE 11-18 Oesophageal duplication cyst. A 44-year-old woman presented ■with complaint of food stuck in her throat. (A) Chest radiograph shows an opacity causing rightward displacement of the azygo-oesophageal line. (B) Barium oesophogram demonstrates leftward deviation of distal oesophagus. (C) CT demonstrates a thin-walled cystic lesion abutting the oesophagus. (D) Axial and (E) coronal T2-weighted MR images demonstrate a homogeneous high T2 signal intensity of this mass and no enhancement on the T1-weighted contrast medium-enhanced sequence acquired after contrast agent administration (F).

• FIGURE 11-18 Oesophageal ■duplication cyst. A 44-year-old woman presented with complaint of food stuck in her throat. (A) Chest radiograph shows an opacity causing rightward displacement of the azygo-oesophageal line. (B) Barium oesophogram demonstrates leftward deviation of distal oesophagus. (C) CT demonstrates a thin-walled cystic lesion abutting the oesophagus. (D) Axial and (E) coronal T2-weighted MR images demonstrate a homogeneous high T2 signal intensity of this mass and no enhancement on the T1-weighted contrast medium-enhanced sequence acquired after contrast agent administration (F).

• FIGURE 11-18 Oesophageal duplication cyst. A 44-year-old woman presented with ■complaint of food stuck in her throat. (A) Chest radiograph shows an opacity causing rightward displacement of the azygo-oesophageal line. (B) Barium oesophogram demonstrates leftward deviation of distal oesophagus. (C) CT demonstrates a thin-walled cystic lesion abutting the oesophagus. (D) Axial and (E) coronal T2-weighted MR images demonstrate a homogeneous high T2 signal intensity of this mass and no enhancement on the T1-weighted contrast medium-enhanced sequence acquired after contrast agent administration (F).

• FIGURE 11-18 Oesophageal duplication cyst. A 44-year-old woman ■presented with complaint of food stuck in her throat. (A) Chest radiograph shows an opacity causing rightward displacement of the azygo-oesophageal line. (B) Barium oesophogram demonstrates leftward deviation of distal oesophagus. (C) CT demonstrates a thin-walled cystic lesion abutting the oesophagus. (D) Axial and (E) coronal T2-weighted MR images demonstrate a homogeneous high T2 signal intensity of this mass and no enhancement on the T1-weighted contrast medium-enhanced sequence acquired after contrast agent administration (F).

• FIGURE 11-19 Neurofibroma. A 7-year-old girl with a large ■right apical mass associated with deformity of the adjacent ribs and scoliosis of the thoracic spine (A, B). CT demonstrates a homogeneous low-attenuation mass arising from the posterior mediastinum and extending to the right apex consistent with a plexiform neurofibroma causing mass effect on the trachea and vessels (C, D).

• FIGURE 11-19 Neurofibroma. A 7-year-old girl with a ■large right apical mass associated with deformity of the adjacent ribs and scoliosis of the thoracic spine (A, B). CT demonstrates a homogeneous low-attenuation mass arising from the posterior mediastinum and extending to the right apex consistent with a plexiform neurofibroma causing mass effect on the trachea and vessels (C, D).

• FIGURE 11-19, Continued Sagittal images show that the mass has an isointense signal with chest wall musculature with T1-weighted sequence (E) and hyperintense signal with inversion-recovery sequence (F) imaging.

• FIGURE 11-20 Malignant nerve sheath tumour. A 23-year-old with left ■axillary mass and left shoulder pain. (A) Axial and (B) coronal contrast medium-enhanced CT images show a large heterogeneously enhancing mass in the left axilla, which encases the left subclavian artery. Axial contrast medium-enhanced MR image demonstrates that this enhancing mass expands the neural foramen of the spine, with no erosion of the vertebral body, suggesting that this is a neurogenic tumour (C).

• FIGURE 11-20 Malignant nerve sheath tumour. A 23-year-old with left ■axillary mass and left shoulder pain. (A) Axial and (B) coronal contrast medium-enhanced CT images show a large heterogeneously enhancing mass in the left axilla, which encases the left subclavian artery. Axial contrast medium-enhanced MR image demonstrates that this enhancing mass expands the neural foramen of the spine, with no erosion of the vertebral body, suggesting that this is a neurogenic tumour (C).

• FIGURE 11-21 Paraganglioma. CT of the chest demonstrates an ■enhancing mediastinal mass arising in the middle mediastinum adjacent to the left atrium, and protruding into it (A). I-131 metaiodobenzylguanidine (MIBG) scintigraphy shows increased uptake, revealing that it is a paraganglioma (B).

• FIGURE 11-21 Paraganglioma. CT of the chest demonstrates ■an enhancing mediastinal mass arising in the middle mediastinum adjacent to the left atrium, and protruding into it (A). I-131 metaiodobenzylguanidine (MIBG) scintigraphy shows increased uptake, revealing that it is a paraganglioma (B).

• FIGURE 11-22 ■Extramedullary hematopoiesis. Axial contrast medium-enhanced CT images optimised for (A) soft tissue and (B) bone of a 40-year-old woman with thalassaemia display bilateral soft-tissue masses closely associated with the ribs and the spine. The ribs are expanded by trabeculated bone.

• FIGURE 11-23 ■Lymphangioma. A 56-year-old man found to have a right paratracheal opacity on chest radiograph (A). CT shows a smooth, well-defined right paratracheal lesion which has no perceptible wall and is of fluid attenuation (B). After surgical resection pathological examination revealed lymphagioma.

• FIGURE 11-24 ■Liposarcoma. A 58-year-old man with gradually worsening dyspnoea was found to have a large anterior mediastinal mass when evaluated by chest CT. This mass has a predominantly fat attenuation with internal thick septations and mural nodules and exerts significant mass effect upon the airway (A). PET-CT shows significant FDG uptake of the soft tissue components of the mass (B).

• FIGURE 11-25 Mediastinal ■abscess. An 83-year-old man had a contrast medium-enhanced CT of the chest (A–D) caused by persistent fever and chest pain following mitral valve replacement and ascending aortic graft repair. There is a large fluid collection with peripheral enhancement consistent with an abscess located posterior to the sternum and in close association with the aortic graft (A).

• FIGURE 11-25 Mediastinal ■abscess. An 83-year-old man had a contrast medium-enhanced CT of the chest (A–D) caused by persistent fever and chest pain following mitral valve replacement and ascending aortic graft repair. There is a large fluid collection with peripheral enhancement consistent with an abscess located posterior to the sternum and in close association with the aortic graft (A).

• FIGURE 11-26 Fibrosing mediastinitis. Contrast medium-■enhanced CT shows a partially calcified mediastinal and hilar mass consistent with fibrosing mediastinitis secondary to histoplasmosis in a child with chronic cough and facial swelling. The mass causes stenosis of the superior vena cava (A), right upper lobe and mainstem bronchi (A, B) and right pulmonary artery (C). There are numerous mediastinal venous collaterals in the anterior mediastinum (A, B).

• FIGURE 11-26 Fibrosing mediastinitis. Contrast medium-enhanced CT shows ■a partially calcified mediastinal and hilar mass consistent with fibrosing mediastinitis secondary to histoplasmosis in a child with chronic cough and facial swelling. The mass causes stenosis of the superior vena cava (A), right upper lobe and mainstem bronchi (A, B) and right pulmonary artery (C). There are numerous mediastinal venous collaterals in the anterior mediastinum (A, B).

• FIGURE 11-27 Ring ■around the artery sign. A 13-year-old girl presented with chest pain and a burning sensation in the throat. Lateral projection of chest radiograph demonstrates a lucent line encircling the right pulmonary artery (black arrow), indicating that the mediastinal air is tracking into the right hilum.

• FIGURE 11-28 ■Continuous diaphragm sign in pneumomediastinum. Frontal chest radiograph shows an uninterrupted outline of the diaphragm indicative of a pneumomediastinum.

• FIGURE 11-29 Pneumomediastinum on CT. A 19-year-old ■ woman presents with 3 days of nausea, vomiting and retrosternal chest pain. (A) Chest radiograph shows vertical lucent lines in the neck extending into the mediastinum. (B–D) Axial and (E) coronal reformatted CT images demonstrate air tracking around the mediastinal structures. The presence of fine septations in the air-containing areas is a typical finding of pneumomediastinum, not seen with pneumothorax or pneumopericardium.

• FIGURE 11-29 Pneumomediastinum on CT. A 19-year-old ■ woman presents with 3 days of nausea, vomiting and retrosternal chest pain. (A) Chest radiograph shows vertical lucent lines in the neck extending into the mediastinum. (B–D) Axial and (E) coronal reformatted CT images demonstrate air tracking around the mediastinal structures. The presence of fine septations in the air-containing areas is a typical finding of pneumomediastinum, not seen with pneumothorax or pneumopericardium.

• FIGURE 11-29 Pneumomediastinum on CT. A 19-year-old ■ woman presents with 3 days of nausea, vomiting and retrosternal chest pain. (A) Chest radiograph shows vertical lucent lines in the neck extending into the mediastinum. (B–D) Axial and (E) coronal reformatted CT images demonstrate air tracking around the mediastinal structures. The presence of fine septations in the air-containing areas is a typical finding of pneumomediastinum, not seen with pneumothorax or pneumopericardium.

• FIGURE 11-30 Pericardial cyst. (A, B) Frontal and lateral ■chest radiographs of a 33-year-old woman show an abnormal mass-like contour of the left ventricle. (C) Axial and (D) coronal contrast medium-enhanced CT images demonstrate a mass of fluid attenuation without internal enhancement and no perceptible wall, located anterior and to the left of the heart.

• FIGURE 11-30 Pericardial cyst. (A, B) Frontal and lateral ■chest radiographs of a 33-year-old woman show an abnormal mass-like contour of the left ventricle. (C) Axial and (D) coronal contrast medium-enhanced CT images demonstrate a mass of fluid attenuation without internal enhancement and no perceptible wall, located anterior and to the left of the heart.

• FIGURE 11-31 Pericardial effusion. A 27-year-old man with chronic ■kidney disease presented with dyspnoea. Chest radiographs (A, B) of an enlarged cardiac silhouette since prior examination 6 months ago (C). The ‘sandwich sign’ (arrow) represents the pericardial effusion (B). (D) Steady-state free precession coronal MR image demonstrates uniformly hyperintense fluid in the pericardial sac, confirming the pericardial effusion.

• FIGURE 11-31 Pericardial effusion. A 27-year-old man with ■chronic kidney disease presented with dyspnoea. Chest radiographs (A, B) of an enlarged cardiac silhouette since prior examination 6 months ago (C). The ‘sandwich sign’ (arrow) represents the pericardial effusion (B). (D) Steady-state free precession coronal MR image demonstrates uniformly hyperintense fluid in the pericardial sac, confirming the pericardial effusion.

• FIGURE 11-32 Pericardial haemorrhage. A 63-year-old with ■diaphoresis and tachypnoea. Chest radiograph (A) shows enlargement of the cardiac silhouette since a previous radiograph obtained 10 months ago (B). Contrast medium-enhanced axial CT images (C, D) demonstrate a large high-attenuation fluid collection in the pericardium representing haemorrhage. The patient’s symptoms suggest that there is tamponade physiology.

• FIGURE 11-32 Pericardial haemorrhage. A 63-year-old with ■diaphoresis and tachypnoea. Chest radiograph (A) shows enlargement of the cardiac silhouette since a previous radiograph obtained 10 months ago (B). Contrast medium-enhanced axial CT images (C, D) demonstrate a large high-attenuation fluid collection in the pericardium representing haemorrhage. The patient’s symptoms suggest that there is tamponade physiology.

• FIGURE 11-33 Pericarditis. A 30-year-old man ■with new-onset of left-sided chest pain. Axial contrast medium-enhanced CT shows diffuse pericardial thickening and a moderate-sized pericardial effusion. This was caused by viral pericarditis.

• FIGURE 11-34 Constrictive pericarditis. A 48-year-old man ■ with end-stage renal disease presented with chronic shortness of breath and poor exercise tolerance. Axial unenhanced (A) and contrast medium-enhanced (B) CT images demonstrate pericardial calcification most pronounced in the region of the atrioventricular groove. There is flattening and indentation of the free wall of the right ventricle and the base of the left ventricle. (C) Three-dimensional reconstruction in the two chamber short-axis plane of the heart shows the belt-like calcification surrounding the heart.

• FIGURE 11-34 Constrictive pericarditis. A 48-year-old man ■ with end-stage renal disease presented with chronic shortness of breath and poor exercise tolerance. Axial unenhanced (A) and contrast medium-enhanced (B) CT images demonstrate pericardial calcification most pronounced in the region of the atrioventricular groove. There is flattening and indentation of the free wall of the right ventricle and the base of the left ventricle. (C) Three-dimensional reconstruction in the twochamber short-axis plane of the heart shows the belt-like calcification surrounding the heart.

• FIGURE 11-35 Pericardial metastasis. A 56-year-old man with ■stage IV non-small cell lung cancer. Axial contrast mediumenhanced CT images (A, B) demonstrate nodular thickening of the pericardium (white arrow) representing metastases. CT image optimised for the lung (C) demonstrates a speculated nodule in the right upper lobe consistent with known non-small cell lung cancer.

• FIGURE 11-35 Pericardial metastasis. A 56-year-old man with ■stage IV non-small cell lung cancer. Axial contrast mediumenhanced CT images (A, B) demonstrate nodular thickening of the pericardium (white arrow) representing metastases. CT image optimised for the lung (C) demonstrates a speculated nodule in the right upper lobe consistent with known non-small cell lung cancer.

• FIGURE 11-36 Mesothelioma. Contrast ■medium-enhanced CT images demonstrate confluent left pleural thickening extending into the oblique fissure caused by mesothelioma (A). Nodular pericardial thickening indicates pericardial involvement (B).