Clinical Imaging/Thorax as a Region PDF

👔 Topic 5 - Clinical Imaging/Thorax as a Region Lecture 1 - Clinical Imaging What is Conventional Radiology (Plain Radiographs) Radiography uses X-rays for digital 2D image creation...

👔 Topic 5 - Clinical Imaging/Thorax as a Region Lecture 1 - Clinical Imaging What is Conventional Radiology (Plain Radiographs) Radiography uses X-rays for digital 2D image creation X-ray images (radiographs) are obtained by passing X-rays through a patient onto a detector or film. Posterior Anterior (PA) projection involves the X-ray entering from the patient's posterior aspect and exiting anteriorly to reach the detector/film. AP radiograph is the opposite of PA. Radiographs are typically viewed with a standard orientation, as if the patient is facing you, with feet and hands appearing as if you are looking at your own. Topic 5 - Clinical Imaging/Thorax as a Region 1  Conventional Radiology - what colours identifies what Dense tissues absorbs/reflects more X-rays, making them "radiopaque/radiosense" Fewer X-rays reaching the detector → bright area Less dense tissues are "radiolucent" → allows more X-rays to pass through. Air appears black on the X-ray image. Fat is depicted as dark grey. Soft tissue appears as brighter grey. Bone appears white metal appears even whiter. What are X Rays - safety issue, Rule of Distance, Shadow Rule X-rays have higher frequency + shorter wavelengths energy to ionize atoms + disrupt molecular bonds —> harm living tissues. The intensity of the X-ray beam decreases with the square of the distance from the source. Doubling the distance reduces exposure by 4x Similar to shadows: Closer to the light source (farther from the wall), the image is larger. Closer to the wall, the image is sharper. Contrast Media/Agent Radiopaque fluids like iodine/barium are used in medical imaging. administered through intravenous (IV)/oral routes/catheter into various cavities fluids enable the study of luminal or vascular organs What is Fluoroscopy 2D imaging technique using continuously emitted X-rays for real-time imaging. Often used to assess the GI Tract Provides insight into the morphology + motility of these organs. Topic 5 - Clinical Imaging/Thorax as a Region 2  What is Computed Tomography (CT) imaging technique using X-rays to create tomographic images. Patients lie supine on a scanner table and pass through the CT gantry (X-ray tube and detectors that rotate around the patient.) A computer uses X ray projections to reconstruct images. How are CT/MRI images viewed CT images (and MRI) are viewed as if you are standing. Axial: at supine, patient’s feet Coronal: facing patient Sagittal: patient’s left side What are MRI Scans imaging technique that uses magnets and radio waves to create detailed cross- sectional images. Topic 5 - Clinical Imaging/Thorax as a Region 3  machine generates a strong magnetic field → excites the nuclei of atoms in your body. Radio waves temporarily disrupt this alignment —> the nuclei emit energy signals that vary in different tissues. These signals are detected by a coil around your body. doesn't involve harmful radiation and is safe during pregnancy, and for children. People with metal objects inside their body should not have an MRI due to the risk of injury. What is Ultrasonography/Ultrasound Ultrahigh frequency sounds Bounces off due to changes in density high density = brighter bone reflected nearly all ultrasound waves - not used for CNS Ultrasound is operator-dependant It can't be used on the adult brain because bones reflect most ultrasound waves. It's not suitable for checking the lungs either, as air doesn't work well with it. gel is used to get better images and avoid interference. Doppler ultrasound measures the speed like blood flow using frequency shifts For abdominal ultrasounds, having a full bladder helps by acting like a "window" and transmits sound through Topic 5 - Clinical Imaging/Thorax as a Region 4  What is Nuclear Medicine Imaging Nuclear Medicine Imaging (NMI) reveals info about the spread and concentration of small amounts of radioactive substances in the body. A radioactive compound is attached to a substance that a specific organ absorbs. A detector displays where the radiotracer is in the body. It's used for diagnosis and to treat cancer, where radiotracers gather in tumours and emit particles that kill cancer cells. What is PET Positron Emission Tomography → specialized type of nuclear medicine imaging. uses isotopes with very short half-lives that emit positrons. PET assesses organ function in real-time, showing areas with increased glucose uptake through an injected isotope, detect cancer. radioisotope is fluorodeoxyglucose (FDG), a glucose-like substance, which degrades and emits radiation which is detected What is Endoscopy Endoscopy looks inside the body using an endoscope. An endoscope is typically a slender tube with a light and camera. It's inserted through natural openings like the mouth, nose, anus, or urethra. Laparoscopy - (Keyhole Surgery) Topic 5 - Clinical Imaging/Thorax as a Region 5  Lecture 2 - Thorax as a Region what 5 key things occur during respiratory development Formation of the Respiratory Diverticulum Tracheoesophageal Separation Formation of the Bronchial Tree Development of Alveoli Surfactant Production Topic 5 - Clinical Imaging/Thorax as a Region 6  What week and where does the Respiratory Diverticulum form 4th week the lung bud forms as an outgrowth from the foregut What is tracheoesophageal separation The respiratory diverticulum elongates and eventually separates from the foregut, forming the trachea (windpipe) and oesophagus. What is the Anatomy of the respiratory system Two lungs Air passages: Nostrils (external nose) Nasal cavity Topic 5 - Clinical Imaging/Thorax as a Region 7  Pharynx Larynx Trachea Primary, secondary, and tertiary bronchi Pharynx Pharynx is a muscular tube associated to both respiratory and digestive systems, located posteriorly to the nasal, oral cavity + larynx. 3 divisions: Nasopharynx, Oropharynx, Hypopharynx Topic 5 - Clinical Imaging/Thorax as a Region 8  Larynx (C3-C6) Larynx: A fibrocartilaginous tube in the neck's front and centre. Cartilaginous skeleton of the larynx: 3 Paired Cartilages, 3 Single Cartilages (9) Connection between cartilages by Ligaments and muscles vocal fold - controls air flow, the space is the Rima Glottidis (air passes through larynx) arytenoid cartilage controls Rima Glottidis At C6, the inferior margin of the Cricoid Cartillage = end of larynx Topic 5 - Clinical Imaging/Thorax as a Region 9  Trachea (C6-T4/T5) Trachea: A cylindroid structure composed of C-shaped cartilaginous rings connected by ligaments. Posterior wall: Lacks cartilage and contains smooth muscle fibers. Extends from the inferior margin of the cricoid cartilage to the carina (T4/T5), where it divides into left and right principal bronchi. Each bronchus further divides first into lobar, then into segmental branches. Lungs Each lung has: an apex, a base – two (left) + three (right) lobes Topic 5 - Clinical Imaging/Thorax as a Region 10  – three surfaces (costal, mediastinal, and diaphragmatic). – three borders (anterior, inferior, and posterior). 3 Surfaces of the lung What is the Hilum Hilum - entry of the lung, where bronchioles and artery, nerves are located found on the mediastinal surface of the lung Topic 5 - Clinical Imaging/Thorax as a Region 11  What is the Thoracic Cavity Location: Between the neck and the abdominal cavity. Superior limit: Thoracic aperture. Anterolateral boundary: Rib cage and sternum. Inferior boundary: Diaphragm Divisions of the Thoracic Cavity Topic 5 - Clinical Imaging/Thorax as a Region 12  The thoracic cavity can be divided into three areas: right and left pulmonary cavities and the mediastinum. The mediastinum can be divided into superior and inferior mediastinum. The inferior mediastinum is subdivided into anterior, middle, and posterior mediastinum. Topic 5 - Clinical Imaging/Thorax as a Region 13  Pleura Pulmonary cavity lining: smooth lining tissue = pleura or pleural membrane. Forms a complete cavity called the pleural cavity. allows lungs to expand + reduce friction during lung expansion Surface Anatomy of the thorax Topic 5 - Clinical Imaging/Thorax as a Region 14  X-ray of thorax Topic 5 - Clinical Imaging/Thorax as a Region 15