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IMAGING BHAGATH M S
RAJEEV BISWAS
Contents Sl no 1 2,3,4 5 6 7 8 9 10 11 12 13
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General Theory Radiology of Respiratory System Circulatory System Digestive System (1) Plain Abdomen Digestive System (2) Gastrointestinal Tract Digestive System (3) Hepatobiliary System, Spleen & Pancreas Genito-urinary System Bone, Joint & Soft tissue Central Nervous System Head & Neck Interventional Radiology
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Chapter 1. General Theory Information > 5 Radiographic Opacities
To master To master the principle of various medical imaging modalities and the preparation work before examinations. To master the advantages and limitations of various imaging modalities in the diagnosis and treatment of different system disease. To be familiar with
To familiarize with medical imaging diagnostic methods and principles
SENIOR’S NOTE 1. Write about the classification of imaging? > Transmission - X-ray - Computed Tomography > Reflection - Sonograph > Emission - Magnetic Resonance Imaging - Single Photon Emission Tomography - Proton Emission Tomography > Projectional imaging using X-ray - When a bean of X-ray photons penetrate the body, their intensity is reduced as they encounter tissues. - The X-ray exiting the body are captured by a detector. 2. When to require each of them :: X-ray, CT, MRI > X-RAY (are electromagnetic radiation) Properties :: Penetration Photographic (Radiography) Fluorescence effect (Fluoroscopy) Ionization effect (Radiation therapy) Image is the project of the objective between X-ray tube & X-ray film/ detector. Low energy photons are absorbed by patient. Not useful for image production Filters reduce patient exposure PAGE 2
Only possible because of differential penetration of X-ray Objects: Densities & Thickness X-rays: Amount & energy of Photons > CT (Computed Tomography) CT also relies on X-rays transmitted through the body More sensitive X-ray detection system is used, the image consist of sections [slices] through the body, data are manipulated by a computer. Not only fat tissue can be distinguished from other tissue, but also gradations of density within soft tissue can be recognized. Eg: Brain substance from CSF, Tumor from surrounding normal cells. CT angiography, stent in Bronchus, Fracture of knee, CT colonography > MRI The basic principle of MRI depends on the fact that the nuclei of certain elements align with the magnetic force when placed in strong magnetic field. At field strength currently used in Medical Imaging, hydrogen nuclei [protons], in water molecules & lipids are responsible for producing anatomical images MRI is also an established technique for imaging the spine, bones, joint, pelvic organs, liver, biliary system, urinary tract & heart - Anatomy MRI - Blood oxygenation – Level Dependent, (BOLD) FMR - Magnetic Resonance Spectroscopy (MRS) - Diffusion – Tensor Imaging (DTI) - Perfusion MRI (PWI) > FLUROSCOPY Advantage : Observing movement of organs, flexible position, low cost Disadvantage : Low resolution, no permanent record, high radiation exposure - Xray the visibility of both normal structures and depends on differential absorption. - With conventional radiography there are 4 basic densities :: a) gas b) fat c) all other soft tissue d) calcified structure 3.TYPICAL TISSUE FOR EACH TECHIQUE Chest, Bone, GI : X-ray first Neuro, Liver, Pancreas : CT, MRI first 4. FUNDAMENTAL TISSUE DENSITIES OF : NATURAL CONTRAST : Gas, Fat, Water, Mineral, Metal 5. ARTIFICIAL CONTRAST Certain “contrast agents” are delivered into human body, for enhancing contrast between the targeted tissue and adjacent tissues. PAGE 3
- Positive contrast media :: Barium, Iodine agents - Negative contrast media :: Air, CO2, O2 6. PACS SYSTEM Picture achieve communication system (PACS) CT, MRI, General Radiology, Ultrasound, Nuclear Medicine – all nowadays are digital techniques. - Low speed High Speed - 2D 3D - Film Digital - Anatomy Function - Single Imaging Fusion of Multiple imaging - Diagnosis only Diagnosis & Therapy - Multiple Modalities
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2,3,4. Radiology of Respiratory System
Chest X-ray Interpretation A to X
PA view (normal)
Lateral view (normal)
A – Airway (Anatomic & Artificial) [ETT Placement, etc]
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B – Bony Structures Remember to scrutinise every rib, (from the anterior to posterior), the clavicles vetebrae and the shoulders. After scrutinising the bones and soft tissues, remember to look for pathology in the ‘hidden areas’. _ The lung apices _ Look ‘behind’ the heart _ Under the diaphragms.
Hidden areas
C – Cardiac Structure Assessment of heart size _ The cardiothoracic ratio should be less than 0.5. _ i.e. A/B<0.5. _ A cardiothoracic ratio of greater than 0.5 (in a good quality film) suggests cardiomegaly.
CT Ratio = CR + CL / T (CR+CL transverse cardiac diameter, T transverse thoracic diameter (at max TC dia))
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D – Diaphragm Structure
The right hemidiaphragm is ‘higher’ than the left. Both costophrenic angles are sharply outlined.
The outlines of both hemidiaphragms should be clearly visible.
Assess for diaphragmatic flattening. The distance between A and B should be at least 1.5 cm.
_ The right hemidiaphragm is usually ‘higher’ than the left. _ The outline of the right can be seen extending from the posterior to anterior chest wall. _ The outline of the left hemidiaphragm stops at the posterior heart border. _ Air in the gastric fundus is seen below the left hemidiaphragm.
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E – Esophagus, Effusion (Pleural)
Effusion (Pleural)
F – Fissure , Lung Field
G – Gastric Bubble vs Situs
H – Hilum - Lymph Nodes, Airways, Vessels _ Both hilar should be concave. This results from the superior pulmonary vein crossing the lower lobe pulmonary artery. The point of intersection is known as the hilar point (HP). _ Both hilar should be of similar density. _ The left hilum is usually superior to the right by up to 1 cm.
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I – Interstitium disease processes J – Junctional Lines K – Kerley Lines: A, B, C Are a sign seen on chest radiographs with interstitial pulmonary edema. They are thin linear pulmonary opacities caused by fluid or cellular infiltration into the interstitium of the lungs. A Apex B Base C Center
L- Lobes of Lung vs Cardiac Silhouette (Silhouette Sign) The silhouette sign has applications elsewhere in the body too; gas is outlined within bowel lumen separate from soft tissue bowel wall, renal outlines are visible due to the presence of perinephric fat between the kidneys and surrounding soft tissues. The silhouette sign has two uses: i) It can localise abnormalities on a frontal CXR without the aid of a lateral view. For example, if a mass lies adjacent to, and obliterates the outline of, the aortic arch, then the mass lies posteriorly against the arch (which represents the posteriorly placed arch and descending aorta). If the outline of the arch and of the mass are seen separately, then the mass lies anteriorly. ii) The loss of the outline of the hemidiaphragm, heart border or other structures suggests that there is soft tissue shadowing adjacent to these, such as lung consolidation.
M – Mediastinum – Mediastinal Widening, Thymus Size It is useful to consider the contents of the mediastinum as belonging to three compartments: _ Anterior mediastinum: anterior to the pericardium and trachea. _ Middle mediastinum: between the anterior and posterior mediastinum. _ Posterior mediastinum: posterior to the pericardial surface.
Normal but prominent thymus in a child. The thymus shows the characteristic ‘sail shape’ projecting to the right of the mediastinum. This appearances should not be confused with right upper lobe consolidation or collapse. PAGE 9
O – OverAeration, Opacifation P – Pleura Q – Quickly Check for Correct Name, Date of birth, Imaging study, Date & Time R – Respiratory Effort – Inspiratory vs Expiratory film S – Segments , Silhouette Sign Silhouette Sign > Loss of normally visible border of an intrathoracic structure caused by an adjacent pulmonary density.
T – Thoracic Underperfusion – Pulmonary Embolism U – UnderPerfusion. Underpenetration, Underventilation V – Vascularity. Vascular Line Placement (Central Lines, Umbilical Artery/ Vein Lines) W – Women (Breast Shadows) X – Xtra Equipment: Central Lines, ETT, Chest Tubes, etc Right side: _ Superior Vena Cava _ Right Atrium Anterior aspect: _ Right Ventricle Cardiac apex: _ LV Left side: _ LV _ Left atrial appendage _ Pulmonary trunk _ Aortic arch
To master To master the radiological signs of lung disease Air-space filling and Spherical shadows, air containing space and cavity, Pulmonary collapse and Obstructive emphysema. To master the X-ray and CT findings of the pleural lesions ( pleural effusion, pleural thickening, pleural tumors, pleural calcification, pneumothorax, hydropneumothorax) To master the X-ray, CT and MRI findings of the normal mediastinum and some mediastinal masses (retrosternal goitre, thymomas, lymphadenopathy, neurogenic tumors ) To master the X-ray and CT findings of the bacterial pneumonia, lung abscess, pulmonary tuberculosis, carcinoma of the bronchus. To master the mammographic signs of breast carcinoma and benign masses. To be familiar with To be familiar with the general image technology and normal X-ray and CT appearance of Respiratory System. To be familiar with the X-ray, CT and MRI findings of some mediastinal masses (hiatus hernia) To be familiar with the X-ray and CT findings of the pneumomediastinum, hilar enlargement, diaphragm and chest wall. To be familiar with the X-ray and CT findings of the chronic obstructive airway disease and metastatic neoplasms. To be familiar with the X-ray and CT findings of the trauma to the chest
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TO MASTER THE RADIOLOGICAL SIGNS OF LUNG DISEASE AIR-SPACE FILLING AND SPHERICAL SHADOWS, AIR CONTAINING SPACE AND CAVITY, PULMONARY COLLAPSE AND OBSTRUCTIVE EMPHYSEMA. Radiological Signs of lung disease Air- Space Filling (consolidation) - replacement of air in the alveoli by fluid or rarely by other materials - the fluid can be either i) an exudate(emitted by an organism through pores or a wound) ii) a transudate (extravascular fluid with low protein content and a low specific gravity. Primary cell types are mononuclear cells: macrophages, lymphocytes and mesothelial cells. Transudate usually appears more clear than exudate as it has low protein content.)[ Levels of lactate dehydrogenase (LDH) or a Rivalta test can be used to distinguish transudate from exudate.]
- commonly occurs in infection, edema, hemorrhage of lungs Signs - a shadow with ill defined borders - an air bronchogram - the silhouette sign Spherical Shadows (lung mass, lung nodule) Usual causes are :: - Malignant tumor (bronchial carcinoma/ bronchial carcinoid, metastasis) - Benign tumor (hamartoma) - Infective granuloma (tuberculoma) - Other nodules (lung abscess, spherical pneumonia) Air containing space & Cavity - uniform wall thickness - caused by bullae(a larger blister containing serous fluid), lung cyst Pulmonary collapse (atelectasis) - caused by Bronchial Obstruction - collapse caused by bronchial obstruction occurs because air cannot get into the lung in sufficient quantities to replace the air absorbed from the alveoli. - Signs of lobar collapse i) Displacement of structure ii) Consolidation accompanies lobar collapse iii) The silhouette sign - commoner causes : primary carcinoma/ carcinoid tumours - foreign body/ retained mucus plug - invasion or compression (adjacent malignant tumour/ enlarged lymph nodes) Obstructive emphysema _ Characterized by permanent enlargement of alveoli _ Is accompanied by destruction of alveolar walls _ Subdivided into i) diffused emphysema ii) localized emphysema - Sign - Increased lung volume - Attenuation of vessels PAGE 11
TO MASTER THE X-RAY AND CT FINDINGS OF THE PLEURAL LESIONS ( PLEURAL EFFUSION, PLEURAL THICKENING, PLEURAL TUMORS, PLEURAL CALCIFICATION, PNEUMOTHORAX, HYDROPNEUMOTHORAX) Pleural lesion PLEURAL EFFUSION > Free pleural effusion > Loculated pleural effusion - Seen by pleural adhesion - Such loculation may be either periphery of the lung or within the fissure between the lobes. - A loculated effusion may simulate a lung tumour on chest radiology PLEURAL THICKENING > May follow resolution of a fluid > Is nearly always much smaller in volume than the original pleural effusion PLEURAL TUMORS > Commonest pleural tumors :: Metastatic Carcinomas > Primary pleural tumors :: Mesothelioma (relatively uncommon) PLEURAL CALCIFICATION > Irregular plaques of calcium may be seen with or without accompanying pleural thickening > Unilateral pleural calcification is often due to an old empyema or tuberculosis > Bilateral pleural calcification is often related to asbestos exposure > Sometimes no cause for pleural calcification can be found. PNEUMOTHORAX > HYDROPNEUMOTHORAX > A line of pleura > Absence of vessel shadows outside of the line. > The diagnostic feature is the air-fluid level
TO MASTER THE X-RAY, CT AND MRI FINDINGS OF THE NORMAL MEDIASTINUM AND SOME MEDIASTINAL MASSES (RETROSTERNAL GOITRE, THYMOMAS, LYMPHADENOPATHY, NEUROGENIC TUMORS ) Intrathoracic thyroid masses(retrosternal goitre) are the most frequent cause of a superior mediastinal mass. The characteristic feature is that the mass extends from the superior mediastinum into the neck and compress or displaces the trachea. Dermoid cyst and thymomas often confined to the anterior mediastinum. Lymphadenopathy is the next most frequent causes of mediastinal swelling. The typical findings of the lymphadenopathy are lobulated outlines and multiple locations involved. Neurogenic tumors are the commonest causes of the posterior mediastinum. Pressure deformity of the adjacent ribs and thoracic spine is often visible. Calcification occurs in many conditions ,
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but almost never in malignant lymphadenopathy, occasionally, it occur in aneurysms of the aorta.
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TO MASTER THE X-RAY AND CT FINDINGS OF THE BACTERIAL PNEUMONIA, LUNG ABSCESS, PULMONARY TUBERCULOSIS, CARCINOMA OF THE BRONCHUS. BACTERIAL PNEUMONIA The major purpose of chest film is to establish whether or not pneumonia is present. There is considerable overlap in the imaging appearance of various bacterial pneumonias, even fungal ,viral or mycoplasma pneumonia. The basic radiological feature of pneumonia is consolidation varying from a small ill-defined shadow to large shadow involving the whole of one or more lobes. Consolidation may be accompanied by loss of volume of the affected lobe. Cavitation may occur within the consolidated areas. The differentiation between pneumonia and edema or pulmonary infarction may be difficult or impossible radiographically. LUNG ABSCESS A lung abscess is usually seen as a spherical shadow containing a central lucency due to air within the cavity. An air-fluid level may be present
TO MASTER THE MAMMOGRAPHIC SIGNS OF BREAST CARCINOMA AND BENIGN MASSES. - A mass with ill-defined or spiculated borders. - Invasive ductal carcinoma in left upper inner quadrant. - Invasive ductal carcinoma with nonpalpable mass - Clustered, fine linear or irregular calcifications-so called malignant calcifications. - Invasive ductal carcinoma - Ductal carcinoma in situ - Other signs of breast carcinoma are architectual distortion and skin thickening. - Invasive ductal carcinoma - Inflammatory breast carcinoma
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SENIORS NOTES :: THE TYPICAL SIGNS OF PNEUMONIA ? > The basic radiological features of pneumonia is :: - CONSOLIDATION varying from small-ill defined shadow to large shadow involving the whole of one or more lobes - CONSOLIDATION may be accomplished by loss of volume of the affected lobe. - CAVITATION may occur within the consolidated areas. - There may be associated PLEURAL EFFUSION AIR BRONCHOGRAM SIGN Normally it is not possible to identify air in bronchi within normally aerated lung because the walls of normal bronchi are too thin and air filled. Bronchi are surrounded by air in the alveoli, but if the alveoli filled with fluid, the air in the bronchi contrast with fluid in the adjacent sign. This sign is seen to great advantage on CT
The typical signs of LUNG CANCER ? SIGNS OF CENTRAL TUMOR The tumor itself may be present as a hilar mass with or without narrowing of adjacent major bronchus. The collapse and/or consolidation of the lung beyond the tumor due to obstructing bronchus Lung collapse occurs because air is absorbed Consolidation is the consequence of retained sections and secondary infections. SIGNS OF PERIPHERAL TUMOR A peripheral tumor usually presents as a solitary pulmonary nodule/mass on the plain film or chest CT Much smaller cancers, even as small as few millimeters may be discovered on CT Cavitation within the mass. The walls of the cavity are classically thick and irregular but thin wall smooth cavities due to carcinoma do occur.
Primary and secondary TUBERCULOSIS Pulmonary Tuberculosis It is usually divided into Primary & Post primary forms - PRIMARY is the result of first infection with Mycobacterium tuberculosis & usually occurs in childhood. - POST PRIMARY TUBERCULOSIS, usually in adults, is believed to be re-infection, the patient have developed relative immunity following the primary infection Primary Tuberculosis The area of consolidation, known as Ghon focus, develops in the periphery of the lung – usually in the mid or upper zones. Ghon focus is usually small, but it may occasionally involve most of the lobes. - Sometimes the pulmonary consolidation is small that it is invisible. The consolidation often accompanied by visibly enlarged hilar or mediastinal lymph node. This combination of pulmonary consolidation and lymphadenopathy is known as primary complex. In most cases, treated or not the primary complex heals and often calcifies remains visible throughout life Spread of infection via Bronchial tree leads to tuberculous bronchopneumonia Via blood stream resulting in military tuberculosis Post primary Tuberculosis PAGE 14
Usually present with cough, hemoptysis, weight loss, night sweat or malaise It is usually confined in the upper posterior portion of the chest Occasionally it takes the forms of lower or middle lobe bronchopneumonia Initial lesions are multiple small areas of consolidation and often bilateral. Pleural effusion are frequently and may be the only radiographic abnormality. Predominant or solo feature, particularly in non-caucasian, may be mediastinal or hilar lymphadenopathy. If infection progresses, the consolidation may be enlarge and frequently undergo cavitation. May also spread to give widespread bronchopneumonia or military tuberculosis Infection may undergo partial or complete healing at any stage Healing occurs by fibrosis, often with calcification
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CASES
Bilateral pleural effusion
Lupus pneumonia
Child (1 month old) with Thymus gland & relative large heart [NORMAL X-RAY]
Pneumonia (the whole right middle lobe)
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Pneumonia (multi-lobes of bilateral lungs)
•A spherical shadow containing a central lucency due to air within the cavity and an air-fluid level •The lesion is surrounded by ill-defined consolidation
secondary tuberculosis (both upper lobes) The apical and posterior segments of the upper lobes and apical segments of the lower lobes
Bronchiectasis (the right lower lobe) •CT •Location: the right lower lobe •thick-walled, dilated bronchi crowd together •The normal appearance is seen in the left lower lobe
Diamond ring sign: Dilated bronchi and normal sized bronchial artery Emphysema companied by bullae - PA radiography and CT - Increased lung volume: The diaphragm is pushed down and become low and flat; The heart is elongated and narrowed; The intercostal space are widen and more lung lies in front of the heart and mediastinum. - The reduction in size and number of the pulmonary blood vessels can be generalized or localized and it is accompanied by extensive bullae. Central type lung carcinoma (right lung) •Location: the right hilar mass •Density: well-defined spherical shadow, with narrowing of the right middle bronchus and the collapse of the right middle lobe (atelectasis) •The elevation of the right diaphragm Peripheral lung carcinoma (right middle lobe) •Contrast-enhanced scan •Location: the right middle lobe •A lobulated mass with extensive enhancement •Left pleural effusion PAGE 17
Pulmonary metastases (both lung) •Location: the both lung •Numerous well-defined regular nodular shadows of varying sizes
Left pneumothorax •Location: the left outer zone •A line of pleura •Absence of vessel shadows outside of the line •Low density: no vessels in the outer zone •The left lung is compressed, the density of left lung increased(Vessel shadows are thicker in the inner and middle zone) •Mediastinum moving? Inconspicuous Free pleural effusion (left) •Location: the left lower field •The shadow is often homogeneous and lies outside the lung edge, and appears higher laterally than medially. •The left lower lobe is compressed. •The left hemidiaphragm and the left costophrenic angle is obliterated. •Mediastinam moving? Hydropneumothorax (left) •Location: the left outer zone •A line of pleura •Absence of vessel shadows outside of the line •Low density: no vessel in the outer zone •The left lung is compressed, the density of left lung increased •Air-fluid level •The shadow is often homogeneous and lie outside the lung edge. •Mediastinum moving? Malignant mesothelioma of the pleura (left) Lobulated masses based on the pleura
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5. Circulatory System
TO KNOW > Echocardiography is widely used for morphological as well as functional information about the heart. It is excellent for looking at the heart valves, assessing chamber morphology and volume, determining the thickness of the ventricular wall and diagnosing intraluminal masses. > Doppler ultrasound is used to determine the velocity and direction of blood flow through the heart valves and within cardiac chambers. > Radionuclide examinations are used to assess myocardial blood flow and ventricular contractility, but provide little anatomical detail. > Heart size & Shape - changes in transverse diameter of less than 1.5 cm should be interpreted with caution. - An overall increase in heart size may be due to dilatation of one or more cardiac chambers and/or to pericardial effusion. - A potential pitfall is a patient with a severely depressed sternum (pectus excavatum) in whom the cardiac outline may appear enlarged and altered in shape from simple rotation and displacement - Extensive pericardial calcification is seen in patients with constrictive pericarditis. - Left atrial enlargement, Right atrial enlargement (described in question part)
> Diagnostic information provided by cardiac imaging • The structure and mechanical function of the cardiac chambers and valves • Myocardial tissue characteristics, e.g. presence of myocardial scar and/or oedema • Presence of stress-induced, reversible or irreversible perfusion defects in the myocardium • Patency of the coronary arteries > The assessment of the hilar vessels can be more objective since the diameter of the right lower lobe artery can be measured: the diameter at its midpoint is normally between 9 and 16 mm. The size of the vessels within the PAGE 19
lungs reflects pulmonary blood flow. > Increased pulmonary blood flow due to left to right shunts - Atrial septal defect, ventricular septal defect and patent ductus arteriosus are the common anomalies in which there is shunting of blood from the systemic to the pulmonary circuits (so-called left to right shunts), thereby increasing pulmonary blood flow.
> Causes of pulmonary arterial hypertension • Various lung diseases (e.g. cor pulmonale) • Pulmonary emboli • Mitral valve disease • Left to right shunts • Idiopathic pulmonary hypertension
To master To master the standard plain film in evaluating heart size. To master the anterior, posterior, left and right border of the heart on the plain film. To master the term of CTR.-cardiothoracic ratio To master the signs of left and right atrium enlargement on the plain film. To master the reason that can cause pulmonary arterial hypertension To master the appearances of pulmonary venous hypertension. To master the patterns of interstitial oedema and alveolar oedema. To master the reasons of aneurysm of assending and descending aorta. To be familiar with To be familiar with the CT appearance of heart and great vessel. To be familiar with the MRI appearance of heart and great vessel.
REVIEW QUESTIONS 1. WHAT IS THE STANDARD PLAIN FILM IN EVALUATING HEART SIZE ? > Heart size and shape on plain chest radiography > Assessing the main pulmonary artery and pulmonary vasculature > Increased pulmonary blood flow due to left to right shunts > Pulmonary arterial hypertension > Pulmonary venous hypertension > Pulmonary oedema 2. WHAT ARE THEY IN THE ANTERIOR, POSTERIOR, LEFT AND RIGHT BORDER OF THE HEART ON THE PLAIN FILM ? ANTERIOR POSTERIOR Ascending aorta Left atrium Pulmonary artery Left ventricle Right ventricle
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LEFT ď&#x192; Aorta arch ď&#x192; Pulmonary artery ď&#x192; Left atrial appendage ď&#x192; Right ventricle
RIGHT ď&#x192; Superior vena cava/ Ascending aorta ď&#x192; Right atrium
3. THE TERM OF CTR. WHAT ARE THE CTR INFLUENTIAL FACTORS? > CTR : Cardio Thoracic Ratio transverse diameter of the heart > CTR = B/A (đ??śđ?&#x2018;&#x2021;đ?&#x2018;&#x2026; = maximum ) internal diameter of the chest > Normal CTR : 0.4 â&#x20AC;&#x201C; 0.5 > Erect PA films > Influential factors - Body position in photographs - Phase of respiration - Cardiac cycle systole and diastole - Some diseases (pectus excavatum, scoliosis, humpback)
maximum internal diameter of the chest
transverse diameter of the heart
whether or not the heart has increased in size: it is often more useful compared with previous film
4. WHAT ARE THE SIGNS OF LEFT AND RIGHT ATRIUM ENLARGEMENT ON THE PLAIN FILM?
Left atrial Enlargement > Double contour adjacent to the right heart border, usually within the main cardiac shadow > LAA is seen as a bulge below the MPA on the PA view
Right atrial Enlargement > An increase in the curvature of the right heart border > Enlargement of the superior vena cava
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5. WHAT REASON CAN CAUSE PULMONARY ARTERIAL HYPERTENSION ? WHAT ARE THE APPEARANCES OF PULMONARY VENOUS HYPERTENSION ? WHAT ARE THE PATTERNS OF INTERSTITIAL OEDEMA AND ALVEOLAR OEDEMA? a) Causes of pulmonary arterial hypertension â&#x20AC;˘Various lung diseases (pulmonary heart disease) â&#x20AC;˘Pulmonary emboli â&#x20AC;˘Mitral valve disease â&#x20AC;˘Left to right shunts â&#x20AC;˘Idiopathic pulmonary hypertension b) Appearance of pulmonary venous hypertension i) Common causes : - mitral valve disease - left ventricular failure PAGE 21
ii) Normal: lower zone vessels are larger than those in the upper zones iii) Raised: the upper zones vessels enlarge and in severe cases become larger than those in the lower zones; the vessels within the lungs are obscure c) Patterns of interstitial oedema and alveolar oedema [ Two pulmonary oedema patterns Interstitial & Alveolar ] (All patients with alveolar oedema have interstitial oedema ) > Intestinal oedema (Many septa in the lungs which are invisible on the normal chest film , Because of thickened by edema, the peripherally located septa may be seen as line shadows )
- Kerley’s B Line - Outline of the blood vessels become indistinct
> Alveolar oedema ( is a more severe form of edema in which the fluid collects in the alveoli ) - Acute , - Bilateral
- Pulmonary shadowing is usually maximal close to the hila and fades out peripherally > “butterfly” or “ bat′s wing ”
6. WHAT SIGNS OF HEART FAILURE IN PLAIN CHEST FILM? Cardiac enlargement Raised pulmonary venous pressure Pulmonary oedema Pleural effusion(bilateral) 7. WHAT FEATURE OF PULMONARY EMBOLI? > Plain film: normal > Radionuclide lung scans > CT pulmonary angiography: Filling defect within the lumen 8. WHAT OF THE KEY FEATURE OF AORTIC DISSECTION? WHAT TYPES OF THE DISSECTION ? HOW TO TREAT? > The key feature of dissection is a disruption in the intima, which allows high-pressure blood to infiltrate and expand the media. > The classification of aortic dissection (Stanford classification) Type A (ascending aorta) Type B (non-ascending aorta) > Therapy: Type A is typically treated surgically. Type B is typically treated medically
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Cases Left atrial enlargement in a patient with mitral valve disease showing ‘double contour sign’ (the left atrial border has been drawn) & dilatation of the left atrial appendage (arrow)
Pericardial effusion. The heart is greatly enlarged. (Three weeks before, the heart had been normal in shape and size.) The outline is well defined and the shape globular. The lungs are normal. The cause in this case was a viral pericarditis. This appearance of the heart, though highly suggestive of pericardial effusion is not specific to it – a similar appearance can be seen with other causes of cardiac enlargement, e.g. cardiomyopathy.
Enlarged main pulmonary artery in a patient with pulmonary valve stenosis. The bulge of the main pulmonary artery (lower arrow) is clearly greater than normal and at first glance one might be deceived into diagnosing enlargement of the aorta. However, the aortic knuckle is the first ‘bump’ on the left mediastinal border (upper arrow). It projects 2.5–3 cm lateral to the trachea. The pulmonary artery forms the segment immediately below the aortic knuckle.
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Ventricular septal defect in a child. The heart is enlarged and there is obvious enlargement of the pulmonary vessels. The left to right shunt in this case was 3 : 1.
Congestive cardiac failure. There are large bilateral pleural effusions. The heart is enlarged although it is difficult to measure it precisely because the pleural fluid obscures its borders.
Lab cases Calcification of pericardium
Pericardial effusion
Hypertrophic Cardiomyopathy
There is marked left ventricular hypertrophy, especially the ventricular septum.
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Atrial septal defect (ASD) –Left to right shunt –Enlarged right atrium and right ventricle –Increased pulmonary blood flow –Pulmonary hypertension Tetralogy of Fallot –Pulmonary artery stenosis – decrease of pulmonary blood flow volume and enlargement of right ventricle –Ventricular septal defect – hypertension right ventricle, right to left shunt –Overriding aorta – the blood of right and left ventricle, aortic arch enlargment –Right ventricle hypertrophy Multiple calcific plaque The left anterior descending coronary artery narrowness with irregular thick and thin or coarse calcification.
4. Which one is the most possible source of the embolus? A. Deep vein of lower limb B. Superior mesenteric vein(SMV)-portal vein D. Left atrium
E. Renal vein
F. Superior vena cava
5.Which of the following is(are) impossible with respect to the source of the embolus? A. Deep vein of lower limb B. Superior mesenteric vein(SMV)-portal vein D. Left atrium
E. Renal vein
C. Artery of lower extremity
C. Artery of lower extremity
F. Superior vena cava
6. Which of the following imaging technique should be considered when a patient is highly suspected of pulmonary embolism? a. Enhanced CT at venous phase
b. Enhanced CT at pulmonary phase
c. Enhanced CT at aortic phase
d. Plain CT scan
7. Sort out the enhancing phases above.
d-b-c-a
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6,7,8. Digestive System
To master To master : Diagnosis of pneumoperitoneum, intestinal obstruction (Plain Abdomen) To master: Basic descriptive terms, for example, filling defect, meniscus sign. (Gastrointestinal tract) To master: Diagnosis of GI diseases, for example: gastric carcinoma, and differential diagnosis, for example, between benign gastric ulcer and ulcerating malignancy. (Gastrointestinal tract) To master: Diagnosis of some benign and malignant liver and pancreatic diseases. (Hepatobiliary, Spleen, Pancreas) To master: Differential diagnosis; for example, hepatic cyst, hepatic hemangioma and HCC. (Hepatobiliary, Spleen, Pancreas) To be familiar with: Normal appearance of liver, pancreas, and biliary system. To familiarize with CT scan parameter of liver, for example, three phases post-contrast enhanced. (Hepatobiliary, Spleen, Pancreas) To be familiar with To be familiar with Plain abdominal film (Plain Abdomen) To be familiar with: Normal alimentary tract radiography, and other GI diseases, for example, esophageal carcinoma. (Gastrointestinal tract)
TO MASTER : DIAGNOSIS OF PNEUMOPERITONEUM, INTESTINAL OBSTRUCTION (Plain Abdomen) PNEUMOPERITONIUM > Free gas beneath the hemidiaphragm perforation of gas-containing viscus
A sickle shaped translucency beneath the dome of the right hemidiaphragm
Large quantity of free gas beneath both of the hemidiaphragm
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INTESTINAL OBSTRUCTION > Large quantities of gas & fluid with distended loops of bowel Difference between Colon & Small Bowel Colon COLONIC HAUSTRA Present VALVULAE CONNIVENTES Absent NUMBER OF LOOPS Less DISTRIBUTION Periphery DIAMETER 5cm BENDING Big SOLID FAECES May be present
Small bowel Absent Jejunum More Central 3cm Small Absent
> Colon bowel obstruction - Several gas fluid levels at different heights with colon produce a characteristic stepladder appearance. TO MASTER: BASIC DESCRIPTIVE TERMS, FOR EXAMPLE, FILLING DEFECT, MENISCUS SIGN. (GI tract) > Filling Defect :: Contour protruding toward the lumen (absence of barium) – space occupying lesion inside
> Meniscus sign :: Semicircular configuration crater, with the inner margin convex towards the lumen, lesser curvature antrum or body > Crater :: Contour concave towards the lumen (containing barium) – ulcer
TO MASTER: DIAGNOSIS OF GI DISEASES, FOR EXAMPLE: GASTRIC CARCINOMA, AND DIFFERENTIAL DIAGNOSIS, FOR EXAMPLE, BETWEEN BENIGN GASTRIC ULCER AND ULCERATING MALIGNANCY. (Gastrointestinal tract) Gastric Carcinoma > Contour :: - Ulcerative: Meniscus sign (semicircular configuration crater, with the inner margin convex towards the lumen, lesser curvature antrum or body) - Polypoid :: filling defect
- Infiltrative :: narrowing > Mucosal folds :: - destruction, amputation, effusion or disappearance > Mobility :: - stiffness, loss of peristalsis Differential Diagnosis Benign Gastric Ulcer Penetration beyond lumen Round, Sharply circumscribed crater Mucosal folds radiate to crater edge Edematous tissue surrounding an ulcer produces ulcer mound or collar Pliable, presence of peristalsis
Ulcerating Malignancy Intraluminal crater Irregularity of crater Amputation of mucosal folds Nodularity of surrounding mucosa Rigidity of wall
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TO MASTER: DIAGNOSIS OF SOME BENIGN AND MALIGNANT LIVER AND PANCREATIC DISEASES. (Hepatobiliary, Spleen, Pancreas)
Liver Benign Liver Diseases •Hepatic cyst •Hepatic hemangioma •Hepatic abscess •Fatty infiltration of the liver •Cirrhosis of the liver
Malignant Liver Neoplasms •Primary carcinoma •Metastases
Pancreatic disease • Acute pancreatitis • Classification –
Edema（mild）
–
Necrosis（severe）
• Chronic pancreatitis Pancreatic or pancreatic duct calcification：finely stippled, coarse Pancreatic duct: focal strictures and dilated segments, “beaded”dilatation---Characteristic Diffusely atrophic Recurrent episodes of acute pancreatitis
• Pancreatic adenocarcinoma
TO MASTER: DIFFERENTIAL DIAGNOSIS; FOR EXAMPLE, HEPATIC CYST, HEPATIC HEMANGIOMA AND HCC. (Hepatobiliary, Spleen, Pancreas) Hepatic cyst • Congenital，single or multiple • Sharply defined margin, hypodense, water density (attenuation value 0 ~ 15 HU) • C+, no enhancement • Iso- or hyper when with hamorrhage or infection • Small cyst, high CT value（partial volume effect） • Giant cyst: interventional treatment
Hepatic Cavernous Hemangioma • Common benign tumor of liver • Multiple vascular channels lined by single layer endothelial cells supported by thin fibrous septa • Usually solitary & grow slowly, asymptomatic • Giant hemangioma: abdominal discomfort, rupture
HCC - HCC is locally invasive and tends to invade into the portal and portal veins. - Cancer embolus in portal vein
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TO BE FAMILIAR WITH: NORMAL APPEARANCE OF LIVER, PANCREAS, AND BILIARY SYSTEM. TO FAMILIARIZE WITH CT SCAN PARAMETER OF LIVER, FOR EXAMPLE, THREE PHASES POST-CONTRAST ENHANCED. (Hepatobiliary, Spleen, Pancreas)
LAB CASES
Metal Foreign Body In The Alimentary Tract
Coin In The Alimentary Tract
Key In The Alimentary Tract
Dentures In Esophagus
Pneumoperitoneum
Hepatophrenic Transposition Of Colon
Intestinal Obstruction
Esophageal Carcinoma
Esophageal varices
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Gastric Ulcer
Gastric Carcinoma
Gastric Carcinoma (Infiltrate type)
Pneumoperitoneum :: - Sickle shaped free gas beneath the diaphragm - Perforation of gas- containing viscus
Pneumoperitoneum in newborn because of intestinal perforation
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Intestinal Obstruction Several gas-fluid levels at different heights within small bowel produce a characteristic stepladder appearance, mucosal fold like the spring
Intestinal Obstruction with Adhesion
Intestinal Obstruction with Gall stones .
Esophageal carcinoma - filling defect, destruction of mucosal folds, rigid wall - Lumen narrowing, irregular wall, dilatation of proximal lumen
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Esophageal varices - Multiple wormilike filling defects that distort the normal mucosal folds.
Gastric Ulcer (Lesser curvature) - Crater contains barium: contour protruding outward the lumen (profile view) , - Hampton line: 1-2mm, Mucosal edema, Narrow neck sign. - En face view: Radiating folds
En face view: a round barium collection on the wall of the body of the stomach, radiating folds extend directly to ulcer
Gastric carcinoma (ulcerative) Meniscus sign: semicircular configuration crater with the inner margin convex toward the lumen, lesser curvature antrum or body
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bb
Gastric carcinoma (Polypoid) Filling Defect:
Contour protruding toward the lumen (absence of barium)
Gastric carcinoma (Infiltrative type) Narrowing of the antrum, shouldering, stiffness
Duodenal diverticulum arising from the ascending part of duodenum, mucosal fold into the crater
Ulcer in bulb of Duodenum Carcinoma of colon
Carcinoma of caecum Filling defect, destruction of mucosal
narrowing of the lumen, the dilation in the proximal colon
BENIGN GASTRIC ULCER > Penetration beyond lumen > Round, sharply circumscribed > Mucosal folds radiate to crater edge > Edematous tissue surrounding an ulcer produces ulcer mound or collar > Pliable, presence of peristalsis
ULCERATING MALIGNANCY > Intraluminal crater > Irregularity of crater > Amputation of mucosal folds > Nodularity of surrounding mucosa > Rigidity of wall PAGE 33
JEJUNUM
ILEAM
> Featherlike > Mucosal folds â&#x20AC;&#x201C; annular folds
> Tubelike > Longitudinal folds gradually
TECHNIQUE: Enhanced CT scan. FINDINGS: In arterial phase, there was remarkably thickened esophageal wall. In venous phase, multiple vessels were found in the esophageal wall. DIAGNOSIS: Esophageal varices. TECHNIQUE: Barium meal examination. FINDINGS: There was a large filling defect in the body of stomach with irregular margin. DIAGNOSIS: Gastric carcinoma SUGGESTION: Gastroscope
Radiology of Liver
Fatty liver .
Diffused decrease attenuation of liver compared to spleen
Hepatic cyst Sharply defined margin, hypodense, water density (attenuation value 0 ~ 15 HU), C+, no enhancement
Liver abscess - Multifocal areas of low attenuation - Enhancement in wall (annular enhancement) - Fluid centres, with walls that are thicker, more irregular and more obvious compared to the cysts
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Hepatic cavernous hemangioma Well-circumscribed, spherical mass, hypodense, C+ peripheral, nodular-----progressive centripetal filling
Cirrhosis - Nodular liver contour, - atrophy of right lobe, - enlargement of left lobe, - ascites.
Hepatocellular carcinoma - Cirrhosis - a round hypodense mass, - Enhances on arterial phase and washes out on portal venous phase
Radiology of Biliary System CT, MRI, ERCP(Endoscopic Retrograde Holangio-Pancreatography), MRCP(Magnetic Resonance Cholangio-Pancreatography)
Gall stones: Multiple cholesterol stones within the gall bladder
Acute Cholecystitis Enlargement of the gall bladder ( 5cm), the gall bladder wall was thickened ( 3mm) and there was surrounding inflammatory change seen as stranding in the adjacent fat.
Biliary Stones A stones (low intensity) in the lower portion of common bile duct together with dilatation of upper common bile duct.
Carcinoma of bile duct A dilated intrahepatic duct, a mass in the bile duct
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Radiology of Pancreas Acute pancreatitis - Enlargement - density decrease - blurring margins of the pancreas - parapancreatic fluid
Chronic pancreatitis - Pancreatic or pancreatic duct calcification - diffuse atrophy Pancreatic duct: focal strictures and dilated segments, â&#x20AC;&#x153;beadedâ&#x20AC;? dilatation Pancreatic adenocarcinoma A lobulated mass in head, Ductal dilatation: double duct sign Metastases to liver
2
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Chapter 9. Genito-urinary System KEY POINTS Normal genitourinary system imaging performance Typical X-ray findings of positive urinary tract stones Typical findings of urinary tract tumors Typical findings of urinary tuberculosis Typical findings of prostatic enlargement
NORMAL GENITOURINARY SYSTEM IMAGING PERFORMANCE 1) The Plain Film > Renal outlines - Frontal film ( KUB, A-P view ) lying laterally to the psoas muscles and vertebral column at the plane of T12—L3, the left kidney 1-2cm higher 10-16cm in length, 5-6cm in width renal vertebral angle 15-25 - Lateral film: overlapping with vertebral column > The ureters and the bladder For urinary tract disease diagnosis, a plain radiograph of abdomen (front view) should be obtained before any contrast examination because calcification may later be masked by the contrast medium. And calcification is the commonest sign in urinary system radiology. 2) Urography [intravenous urogram] > Kidneys - Parenchyma: Shown 1 min after injection Pelvicaliceal system - Starting shown 2-3 min after injection. 15-30 min shown best. - The films taken at 5, 15, 0 min after injection - A normal calix cup-shaped with sharp edges (3-5 minor calices draining with major calix) (3-4 major calices draining into pelvis) > Pelvis - Funnel shaped, ampullary shaped, bifid shaped > Ureters - 30 min after injection, when calices & pelvis shown satisfied, releasing the compression belt, the ureters shown, about 25-30 cm long, 3-7 mm wide, seen parts of length on one film. > Bladder - 350-500 ml, smooth outline, centrally locating in the pelvis cavity above the articulation of pubis 3) CT > Pre-contrast CT (CT KUB, C-) - Calcification - Renal parenchyma - Periphery tissues > Contrast CT (post-, C+) - Corticomedullary phase: 30-90s after injection, renal arteries and renal cortex enhanced PAGE 37
- Nephrographic phase: 90-120s after injection, renal parenchyma(cortex and medulla) enhanced - Urographic phase: 5-10min after injection, pelvicaliceal system, ureters and bladder enhanced > CTU (CT urography)
TYPICAL X-RAY FINDINGS OF POSITIVE URINARY TRACT STONES -
X-ray positive stones; Single or multiple Homo or heterogenous density Round shaped, oval, irregular or stag horn
TYPICAL FINDINGS OF URINARY TRACT TUMORS CT - solid heterogenous tumors - spherical, lobulated - low density - occasional calcification in tumors - inhomogeneous enhancement MRI - low signal on T1W1 - Inhomogeneous high signal on T1W1 - Inhomogeneous enhancement IVU - Bulging of Renal outline - Visible calcification in the tumor - Displacement or distortion of major and minor calices - Filling defect of destruction renal pelvis and calices Renal Arteriography - Tumor-Blood vessel staining
TYPICAL FINDINGS OF URINARY TUBERCULOSIS Urinary tuberculosis usually coming from a focus of infection in the lung. 90% of infection may be at cortex of the kidneys, and cause cortical granulomas. The infection at medullar of the kidneys may cause abscesses, even rupture renal pelvis, and make cavitation when necrosis draining out; pyonephrosis occurs if the process repeating, then the renal function may be impaired. Calcification is common. Findings Image examination KUB films -
No marked signs except Calcification
IVU
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-
Calcification - or more foci of irregular calcification - autonephrectomy
-
Irregularity of calices - infection in medullar and renal pelvis, causing abscesses, forming cavitation when necrosis draining out, presenting a definite contrast-filled cavity
-
Dilatation of calices - for strictures of the pelvicaliceal system and ureters
-
Bladder and urethra presentations - Irregular bladder wall for inflammatory edema, then fibrosis resulting in a thick-walled small volume bladder
CT and MRI - damaged renal parenchyma with heterogeneous density or signals, small cavities and extrarenal spread. - CT can sensitively demonstrate early calcification
TYPICAL FINDINGS OF PROSTATIC ENLARGEMENT Prostatic enlargement is very common in elderly men, and may cause dysuria. Prostatic enlargement is usually due to benign hypertrophy, may also be due to carcinoma The diagnosis of enlargement is usually made by digital rectal examination
Findings The prostate gland lies next to the base of the bladder, and between the articulation of pubis and the rectum Oval-shaped like a chestnut Less than 5.0 x 4.8 x 4.3cm of an elderly man
To master To master the general imaging technologies and normal X-ray and CT appearance of the urinary tract system. To master the principal imaging features of urinary tract obstruction. To master the typical imaging findings of positive urinary tract stones To be familiar with To be familiar with the typical findings of renal cell carcinoma and urinary tuberculosis.
TO MASTER THE GENERAL IMAGING TECHNOLOGIES AND NORMAL X-RAY AND CT APPEARANCE OF THE URINARY TRACT SYSTEM. Imaging Techniques Ultrasound X-ray PAGE 39
- KUB, Urography, Intravenous urogram Urography, Intravenous urogram CT, CT urography MRI, MRU Radionuclide examination Special techniques - Retrograde & antegrade pyelography - Cystourethrography - Urethrography Normal Appearance (mentioned in key points)
TO MASTER THE PRINCIPAL IMAGING FEATURES OF URINARY TRACT OBSTRUCTION. > The principal feature of obstruction is dilatation of the pelvicaliceal system and the ureter. > The obstructed collecting system is dilated down to the level of the obstructing pathology and demonstrating this level is a prime objective of imaging. Plain films: x-ray opaque stones (X-ray positive stones) IVU: demonstrating the level of urinary tract obstruction and obstruction degree CT and MRI: demonstrating the causes of urinary tract obstruction Special techniques
TO MASTER THE TYPICAL IMAGING FINDINGS OF POSITIVE URINARY TRACT STONES (given above)
LAB CASES
Corticomedullary phase (30-90s, renal arteries and renal cortex enhanced
Nephrographic phase [90-120s, renal parenchyma (cortex and medulla) enhanced]
Urographic phase (5-10min, pelvicaliceal system, ureters and bladder enhanced)
Renal calculi - X-ray positive stone in the left kidney, - overlapping with vertebral column in lateral view
Plain film
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Ureteral calculi - X-ray positive stone in the left ureter with left urinary tract obstruction
IVU
Bladder calculi
- A well-defined edge, imperceptible wall and uniform water density. - The cyst shows no enhancement.
Prostatic enlargement
Renal cyst
Renal cysts (Polycystic kidney)
Bladder carcinoma - A large filling defect in the right side of the bladder; - lobulated edge
Ureteral Carcinoma Renal Pelvic Carcinoma
Renal cell carcinomas A solid heterogeneous mass in the right kidney, approximately spherical, lobulated; inhomogeneous enhancement
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