RADIOLOGICAL INVESTIGATIONS IN MEDICINE.pptx

Radiology

1. PRESENTATION By Dr. AKHABUE S.O

2. OUTLINE What is Radiology? Branches of Radiology: < Radio-diagnosis <Interventional (Therapeutic Radiology) Imaging Modalities: <Plain radiography <Computed Tomography scan (CT scan) <Magnetic Resonance Imaging <Mammography <Thermography <Radio-nuclide Imaging <Special investigations like (HSG, IVU,RUG, Angiography, Fistulography, etc) <Ultrasonography <Interventional Radiology

3. What is Radiology? Radiology is a branch of medicine that deals with radiant energy in the diagnosis and treatment of diseases by using imaging technologies (Modalities).

4. Branches of Radiology Radio-diagnosis: This is the use of various imaging modalities to arrive at a diagnosis about a patient. Interventional (Therapeutic radiology): Also known as radiation oncology, uses radiation to treat diseases such as cancer using a form of treatment called radiation therapy.

5. Imaging Modalities Plain Radiography: Is used routinely for initial assessment of patient, although it has low specificity and sensitivity as compared to other newer modalities. It uses X-rays, X rays are one of the electromagnetic wave spectrum which are produced when fast moving electrons are made to hit a metal target. X-rays are ionizing. Images are produced when the x-ray passes through the body and gets to a receptor which are radiographic films or photographic plates.

6. Cont... X-rays are attenuated according to the body part density. i.e, due to different levels of absorption of x-rays by different tissues. Calcium in bones absorbs x-rays the most, hence they appear white (Maximum attenuation). Fat and other soft tissues absorb less, and look gray.. different shades of grays (depending on their relevant densities). Air absorbs the least , so lungs look black. (Minimum attenuation).

7. USES Medical uses : <For medical imaging. <Diagnostic imaging <Detection of pathology of the skeletal system and some disease processes in soft tissues. e.g arthritis,bone tumors (especially benign bone tumors), fractures, congenital skeletal anomalies, etc. <For identifyng lung diseases such as pneumonia, lung cancer, pulmonary oedema.

8. Cont... Other X-ray uses < In the industrial world, x-ray scanners are often used to detect minute flaws in heavy metal equipments. <X-ray scanners have become standard equipments in airport security. <X-ray have been pivotal in research involving quantum mechanics theory, crystallography, cosmology., etc .

9. Advantages of x-ray machine It is affordable It is readily availables It does not take time

10. Disadvantages It is ionizing It is 2-dimensional.

11. Computed Tomography Scanning This refers to a computerized x-ray imaging procedure in which a narrow beam of x-rays is aimed at a patient and quickly rotated around the body, producing signsls that are processed by machine’s computer to generate cross-sectionsl images --or ‘slices’’---of the body. These slices are called tomographic images and contain more detailed information than conventional x-rays.

12. CT SCAN -USES Diagnose muscle and bone disorders- such as bone tumors and fractures. Pinpoint the location of a tumor, infection or blood clot. Guide procedures such as surgeries, biopsy and radiation therapy. Detect and monitor diseases and conditions - such as cancer , heart disease, lung nodules and liver masses. Monitor the effectiveness of certain treatments, such as cancer treatment. Detects internal injuries and internal bleeding.

13. Types of CT Head or brain Ct Neck CT CT of the chest Abdominal and pelvic CT (CT scanning of the abdomen) Sinus CT Spine CT CT Angiography (computed tomography technique used to visualize arterial and venous vessels throughout the body).

14. Advantages It gives 4-dimensional images. Hence diagnosis can be made faster within a breath hold. It can be used for staging of malignancies It can image the brain, unlike conventional x-ray machines. It can be reconstructed ( a mathematical process that generates tomographic images from X-ray projection data acquired at many different angles around the patient). It has high sensitivity.

15. Disadvantages It is expensive It is not readily available It is ionizing-- high radiation dose (dose is about 200times to that of a conventional x-ray).

16. MAGNETIC RESONANCE IMAGING (MRI) A magnetic resonance imaging (MRI) uses a strong magnetic field and radio waves to create to create detailed images of the organs and tissues within the body. MRI looks at both body’s structure and function. It distinguishes between fat, muscles, compact bone and bone marrow, brain and spinal cord,fluid filled cavities, ligaments, etc. An MRI scan uses a large magnet, radio waves, and a computer to create a detailed cross-sectional image of the patient’s internal organs and structures. The scanner itself typically looks like a large tube with a table in the middle, allowing the patient to slide inside the tunnel. An MRI scan differs from CT scan and X-rays because it does not use ionizing radiations that can be potentially harmful to a patient.

17. USES Detects abnormalities of the brain and spinal cord Detects tumors, cysts, and other abnormalities in various parts of the body. Injuries or abnormalities of the joints, such as back pain. Certain types of heart problems Diseases of the liver and other abdominal organs Causes of pelvic pains in women (e.g fibroids, endometriosis, etc) Suspected uterine abnormalities in women undergoing evaluation for infertility. Detects abscesses. Detects infections.

18. Advantages It is non-ionizing It gives four dimensional images..( i.e in Axial, coronal, sagittal and multiple oblique planes with equal ease). It gives the best soft tissue contrast of all the imaging modalities. It can be reconstructed. DISADVANTAGES It is not used by patient with metallic implant due to powerful magnetic fields and strong fluctuating radio signals to which the body is exposed. It is expensive it is not readily available It can not image the bones.

19. Mammography A technique for projecting an x-ray image of soft tissue of the breast. It visualizes both the anatomy and pathologies of the breast. It uses very low x-ray dose to visualize the breast. Mammography is the most effective screening method for rear diagnosis of small, palpable breast tumours. This procedure may be some what painful for the woman, because of compression of breast is needed for radiological imaging.

20. TYPES Screening (performed in asymptomatic women, >35 years of age).. Diagnostic (performed in symptomatic women). NB: In women <35 years, ultrasound is performed for screening. This is due to radiation risk.. Regular mammography carries a cumulative risk due to radiation.

21. Advantages It can detect lumps It can detect cancer of the breast DISADVANTAGES It is ionizing It is not readily available

22. ULTRASONOGRAPHY Ultrasonography is a technique, uses echoes of the ultrasound pulses to delineate objects or areas of different densities in the body. Ultrasonography scan the body using high frequency sound waves to produce image on a screen. The basic component of any diagnostic ultrasound system is it’s specialized transducer. The transducer converts electrical impulses to ultrasonic waves at a frequency greater than 1 million cycles per second. These ultrasonic frequencies are transmitted into tissues through a transducer placed on skin.

23. Cont... Ultrasound is not effective in the presence of bone or gas in the gastrointestinal tract. The image produced can be 2D, 3D, 4D etc and can be recorded on video tapes or printed to provide a permanent record known as echogram or sonogram. Ultrasonography does not expose the patient to radiation and contrast medium, but the quality of the image obtained using ultrasound is highly dependent on the skill of the person performing the exam. As there is no ionizing radiation with this modality, it is particularly useful in imaging of children and pregnant women. Water soluble gel is placed on the skin to maintain air tight contact between the skin and the transducer, because ultrasonic waves does not travel well through air.

24. Advantages It is non-ionizing/ non invasive It is safe for pregnant patients and children It is rapid and painless Readily available It is cheap It requires less time manipulations than the other intraoerative diagnostic procedure it can be used for dynamic studies It can be used for Doppler studies (Doppler Ultrasound Scan) It can be mobile It can be used for guided biopsy, interventional radiology It is good for cysts/ cystic structures and fetus in the amniotic fluid.

25. DISADVANTAGES It can not image bones and gas filled structures ( they absorb ultrasound beam). Poor penetration through bone or air Limited penetration in obese patient Highly dependent on operator skill

26. CATEGORIES There are 3 main categories of ultrasound imaging, including: <Pregnancy ultrasound scan <Diagnostic USS <Ultrasound guidance for procedures .

27. USES Ultrasonography is a useful adjunct in the diagnosis of the following; < Space occupying lesions in the neonatal brain : The ECHOENCEPHALOGRAM will show a shift of the brain caused by tumors <It can distinguish between a cystic and solid tumor mass in the kidney, pancreas, liver, ovaries and testies. <It is the best imaging technique in patient with gallbladder diseases. <It can be used to identify breast lump and cyst < Can be used to assess the thyroid for nodules or lesions within the gland. It is particularly useful in early diagnosis of pulmonary embolism It is useful to determine the need for a caesarean section Useful to identify the gender to detect foetal abnormalities For estimation of gestational age of fetus, etc.

28. INTERVENTIONAL RADIOLOGY A subspecialty of radiology that focuses on the diagnosis and treatment of patients utilizing minimally invasive interventional techniques (non-surgical procedures) These inlude: Imaging and treatment of blood vessels (Angiography) Biopsy procedures Cardiac catherization Angioplasty (ballon dilation of blood vessels) Stents Lasers treatment of varicose veins fluid abscess drainage.