introduction radiologica anatomy.pdf

Anatomy year one Radiologi cal ANATOM Y Prof. Talib...

Anatomy year one Radiologi cal ANATOM Y Prof. Talib Jawad 2024 ‫ ص‬07:30 06/05/2024 Who Discovered X-Rays? The Accidental Discovery of X-Rays The scientific and medical communities will forever be indebted to an accidental discovery made by German physicist Wilhelm Conrad Röntgen in 1895. Röntgen originally set out to research the electrical charges or cathode rays created in vacuum tubes known as Crookes tubes. While experimenting with electrical currents through glass cathode- ray tubes, Röntgen discovered that a piece of barium platinocyanide glowed even though the discharge tube was encased in thick black cardboard and was across the room [source: Britannica ‫فيلهلم رونتجن‬ ‫ي عام ‪ ،1895‬قام فيلهلم رونتجن بتسليط شعاع إلكتروني داخل أنبوب زجاجي مطبق بين ‬ ‫طرفيه توتر كهربائي مرتفع‪.‬كان هذا األنبوب مفر ً‬ ‫غا من الهواء‪ ،‬وتنطلق بداخله إلكترونات‬ ‫من قطب كهربائي سالب إلى قطب كهربائي موجب‪.‬أُحيط هذا اإلنبوب بورق ذو لون فاتح‬ ‫ووضعت شاشة فسفورية في نهايته‪.‬‬ ‫لحماية المستخدم من المجال الكهرمغناطيسي المنبعث‪ُ ،‬‬ ‫عندما اصطدم الشعاع اإللكتروني بالشاشة‪ ،‬بدأت بالتوهج‪.‬وعندما وضع ريتشارد رونتجن‬ ‫يده بالصدفة بين األنبوب والشاشة الفسفورية‪ ،‬شاهد صورة لعظام يده على الشاشة‪ ،‬وكانت‬ ‫هذه أول عملية تصوير باألشعة السينية‪.2‬‬ ‫‪ Video: Radiological anatomy | Kenhub‬‬ Radiology is the medical specialty that uses medical imaging to diagnose diseases and guide their treatment, within the bodies of humans and other animals. It began with radiography, but today it includes all imaging modalities, including those that use no ionizing electromagnetic radiation, as well as others that do, such as computed tomography, fluoroscopy, and nuclear medicine including positron emission tomography. Interventional radiology is the performance of usually minimally invasive medical procedures with the guidance of imaging technologies such as those mentioned above.  1- Conventional radiography Conventional radiography involves the use of x-rays; the term “plain x-rays” is sometimes used to distinguish x-rays used alone from x-rays combined with other techniques (eg, CT). For conventional radiography, an x-ray beam is generated and passed through a patient to a piece of film or a radiation detector, producing an image. how conventional radiography it works: X-ray Beam Generation: In conventional radiography, an x- ray beam is generated and directed through the patient’s body. Interaction with Tissues: As the x-rays pass through the body, they interact with different tissues. The denser the tissue, the more it attenuates (absorbs) the x-ray photons.  Image Formation: The x-rays that pass through the patient then hit a piece of film or a radiation detector, producing an image. The resulting image shows variations in tissue density. Radiographic Appearance: The radiographic appearance depends on tissue density : Metal: Appears white (radiopaque) due to its high density. Bone Cortex: Less white than metal. Muscle and Fluid: Gray. Fat: Darker gray. Air or Gas: Appears black (radiolucent)  2- Computerized Tomography (CT) scan Also known as a CAT scan, is a medical imaging technique that provides detailed internal images of the body. What Is a CT Scan? A CT scan combines a series of X- ray images taken from different angles around your body. Computer processing is then used to create cross-sectional images (slices) of various structures inside your body, including bones, blood vessels, and soft tissues1.  How Does It Work? During a CT scan: You lie on a flat bed that enters the CT scanner. The X-ray machine rotates around you, capturing several images. The doctor may ask you to breathe in, out, or hold your breath at certain times during the procedure. It’s essential to remain still during the scan.  If a contrast material (a dye) is used, it may be given as a drink, injected, or administered through the rectum as an enema. The contrast material helps obtain better images of specific areas1. Angiogram of the brain showing a transverse projection of the vertebro basilar and posterior cerebral circulation. Why CT scan Used? Normal results indicate no abnormalities. Abnormalities reported may include the presence of tumors, fractures, blood clots, etc.1. CT scans are valuable for diagnosing various conditions, including: Irritable bowel syndrome Fatty liver Gallstones Lung nodules Cancer Diverticular disease Stroke Bone tumors Brain tumors a The swirl sign (arrow): rotation of the superior Rhabdomyolysis mesenteric artery and vein. b Small bowel obstruction Aortic dissection (arrow): multiple dilated bowel loops with air-fluid levels Kidney stones1. 3- Ultrasonography Or sonography is a technique that visu- alizes superficial or deep structures in the body by record- ing pulses of ultrasonic waves reflecting ‫الموجات فوق‬ ‫الصوتية‬off the tissues (Fig. 1.49). Ultrasonography has the advantage of a lower cost than CT and MRI, and the machine is portable. The technique can be performed virtually anywhere, including the clinic examination room, bedside, or on the operating table..  A transducer in contact with the skin generates high-frequency soundwaves ‫يولد محول الطاقة المالمس للجلد موجات‬ that pass through the body and reflect ‫صوتية عالية التردد تمر عبر الجسم‬ off tissue interfaces between tissues of ‫وتعكس واجهات األنسجة بين األنسجة‬ differing characteristics, such as soft tissue and bone. Echoes from the body ‫ مثل األنسجة‬، ‫ذات الخصائص المختلفة‬ reflect into the transducer and convert ‫ تنعكس أصداء الجسم في‬.‫الرخوة والعظام‬ to electrical energy..‫محول الطاقة وتتحول إلى طاقة كهربائية‬ The electrical signals are recorded ‫يتم تسجيل اإلشارات الكهربائية وعرضها‬ and displayed on a monitor as a ‫ والتي‬، ‫على الشاشة كصورة مقطعية‬ cross-sectional image, which can ‫يمكن عرضها في الوقت الفعلي وتسجيلها‬ be viewed in real time and.‫كصورة واحدة أو على شريط فيديو‬ recorded as a single image or on videotape.  A major advantage of ultrasonography is its ability to produce realtime images, demonstrating motion of structures and flow within blood vessels. In Doppler ultrasonography, the shifts in frequency between emitted ultrasonic waves and their echoes are used to measure the velocities of moving objects. This technique is based on the principle of the Doppler effect. Blood flow through vessels is displayed in color, superimposed on the two-dimensional cross-sectional image. ‫الميزة الرئيسية للتصوير بالموجات فوق الصوتية هي قدرته على إنتاج صور في الوقت‬.‫ توضح حركة الهياكل والتدفق داخل األوعية الدموية‬،‫الحقيقي‬ ‫ تُستخدم التحوالت في التردد بين الموجات فوق‬،‫في التصوير بالموجات فوق الصوتية بالدوبلر‬ ‫ تعتمد هذه التقنية على مبدأ‬.‫الصوتية المنبعثة وأصدائها لقياس سرعات األجسام المتحركة‬ ‫ متراكبًا‬،‫ يتم عرض تدفق الدم عبر األوعية باأللوان‬.‫تأثير دوبلر‬ Scanning of the pelvic viscera Scanning of the pelvic viscera from the surface of the abdomen requires a fully distended bladder. The urine serves as an "acoustical window ‫نافذة‬ ‫صوتية‬," transmitting soundwaves to and from the posteriorly placed pelvic viscera with minimal attenuation ‫باقل قدر من الوهن‬. The distended bladder also displaces gasfilled intestinal loops out of the pelvis. Transvaginal ‫خالل المهبل‬sonography permits the positioning of the transducer closer to the organ of interest (e.g., the ovary) and avoids fat and gas, which absorb or reflect soundwaves. Bone reflects nearly all ultrasound waves, whereas air conducts them poorly. Consequently, the CNS and lungs of adults cannot be examined by ultrasonography. The appeal ‫ جاذبية‬of ultrasonography The appeal ‫ جاذبية‬of ultrasonography in obstetrics is that it is a non-invasive procedure that does not use radiation; it can yield useful information about the pregnancy, such as determining whether it is intrauterine or extrauterine (ectopic) and whether the embryo is living. It has also become a standard method of evaluating the growth and development of the embryo and fetus.  4- Magnetic resonance imaging (MRI) ‫التصويربالرنين المغناطيسي‬ MRI is widely used in hospitals and clinics for medical diagnosis, staging and follow-up of disease. Compared to CT, MRI provides better contrast in images of soft tissues, e.g. in the brain or abdomen. However, it may be perceived as less comfortable by patients, due to the usually longer and louder measurements with the subject in a long, confining tube, although "open" MRI designs mostly relieve this.  Medical imaging techniques Medical imaging techniques enable the visualization of normal anatomy in the living. This allows us to view structures with their nor- mal tonus, fluid volumes, internal pressures, etc., which are not present in the cadaver. The primary goal of medical imaging is, of course, to detect pathology. However, a sound knowledge of radio- logical anatomy is required to distinguish pathologies and abnormalities from normal anatomy.  is a medical imaging technique used in radiology to form pictures of the anatomy and the physiological processes inside the body. MRI scanners use strong magnetic fields, magnetic field gradients, and radio waves to generate images of the organs in the body. MRI does not involve X-rays or the use of ionizing radiation, which distinguishes it from computed tomography (CT) and positron emission tomography (PET) scans. MRI is a medical application of nuclear magnetic resonance (NMR)) which can also be used for imaging in other NMR applications, such as NMR spectroscopy. Magnetic resonance imaging - Wikipedia 5- Nuclear medicine imaging What is nuclear medicine imaging? Nuclear medicine imaging is a method of producing images by detecting radiation from different parts of the body after a radioactive tracer is given to the patient. The images are digitally generated on a computer and transferred to a nuclear medicine physician, who interprets the images to make a diagnosis.  Radioactive tracers used in nuclear medicine are, in most cases, injected into a vein. For some studies, they may be given by mouth. These tracers aren’t dyes or medicines, and they have no side effects. The amount of radiation a patient receives in a typical nuclear medicine scan tends to be very low. Nuclear Medicine Imaging: What It Is & How It's Done (clevelandclinic.org) Why would you need a nuclear imaging test? Nuclear imaging is used primarily to diagnose or treat illnesses. Conditions diagnosed by nuclear medicine imaging include: Blood disorders. Thyroid disease, including hypothyroidism. Heart disease. Gallbladder disease. Lung problems. Bone problems, including infections or breaks. Kidney disease, including infections, scars or blockages. Cancer.