General Radiology Basics PDF

General Radiology - PHA 649P The Basics Bernadette Evitt, MCMS, PA-C Barry PA Program 1  Objectives Explain what an X-ray and fluoroscopy, including when these imaging modalities are indicated or contraindicated. Discuss the p...

General Radiology - PHA 649P The Basics Bernadette Evitt, MCMS, PA-C Barry PA Program 1  Objectives Explain what an X-ray and fluoroscopy, including when these imaging modalities are indicated or contraindicated. Discuss the principles of radiation safety. Identify radiographically the cardinal imaging planes and body positioning for imaging. Explain what CT is, and when this imaging modality is indicated or contraindicated. Explain the basic physics of MRI, and when this imaging modality is indicated or contraindicated. Explain image weighting in MRI, as it relates to T1, PD, and T2 images. Develop a basic understanding of the various modalities nuclear imaging studies including indications, contraindications, and radioisotopes used. Explain items that should be included when ordering an imaging study. Understand how to approach reading radiographic images. Define the terms and factors as they relate to radiographic image quality. 2  Imaging Modalities Radiography “conventional radiograph”, “plain films” or “standard film” Fluoroscopy Computed axial tomography “CT” Magnetic resonance imaging “MRI” Ultrasound “US” Nuclear Imaging Interventional radiology “angio” 3 Radiography “conventional radiograph”, “plain films”, or “standard film” Discovered by: Wilhelm Conrad Roentgen on November 8, 1895. Most common imaging Image formed using broad beam ionizing radiation The image formed is related to the subjects’ density “Wet reading” - AKA “STAT” interpretation 4  Digital Radiography PACS - A picture archiving and communication system (PACS) is a computerized means of replacing the roles of conventional radiological film. Picture Archiving Communications System Storage Benefits: Countless images stored Images could be viewed by anyone with the right to view them-ANYWHERE ANYTIME 5  Radiography Indications X-rays can be used to diagnose and treat a variety of conditions, including: – Bone injuries – Infections – Foreign objects – Tumors – Other conditions: X-rays can help diagnose arthritis, osteoporosis, tooth decay, and more. – Plan and evaluate treatments: X-rays can help plan and evaluate treatments for a variety of conditions. – X-rays can also be used therapeutically to destroy cancerous tumors and cells by damaging their DNA. 6 Radiography – Dangers and Contraindications Ionizing radiation in large doses is known to produce free radicals and cell mutations that can lead to many forms of cancer or anomalies. – Radiation associated cancers: Leukemia, Breast Cancer, Thyroid Cancer, Brain Cancer Contraindications – Pregnancy - teratogenic times. Prenatal exposure: highest risks gestational weeks 8-15 – Mental retardation – Reduced head circumference Children and radiation: https://www.cdc.gov/childrenindisasters/radiation- emergencies.html#:~:text=Children%20have%20more%20cells %20that,they%20could%20absorb%20more%20radiation. 7 Radiation Safety 8  Radiation Safety ALARA - "As Low As Children Reasonably – Other methods: U/S or MRI Achievable". – Avoid repeat testing The three primary – Look for an accredited facility: Look for an principles of radiation imaging facility that is safety to minimize accredited and physicians radiation exposure. who are board-certified – Time – Distance – Shielding 9  Fluoroscopy Definition: continuous X-ray image on https://www.youtube.com/ a monitor, much like an X-ray movie. watch?v=4Aq02nrUjKQ Indications: https://www.youtube.com/ – Guiding injection, discography, watch?v=zKd3I3kSD3A Barium enema / barium swallow, Flexion / Extension X-ray, Orthopedic and urological surgery, Angiography and pacemakers, Placement of PICC Contraindications: – Same as x-ray – Patients who are allergic to or sensitive to medications, contrast media, iodine, or latex, kidney failure or other kidney problems 10  Computed Tomography (CT) Developed in the 1970’s Uses X-rays Gives Higher Patient Dose Gives better view of bones Is good for studies with or without contrast for tissue studies Involves sectional anatomy imaging Ability to look at tissue depth - 3D rendering, whereas A basic radiograph would capture the whole loaf of bread as in a photograph. 11 Cardinal Planes Coronal plane: Any vertical plane that divides the body into anterior and posterior (belly and back) sections. Transverse plane: Any plane that divides the body into superior and inferior parts, roughly perpendicular to the spine. Sagittal plane: Any imaginary plane parallel to the median plane. 12 CT - Bone Reconstruction in 3D http://www.youtube.com/watch?v=QvOrlbXgChE The process of digitally creating a 3D model of a bone structure, which can then be used to design and fabricate personalized bone implants through 3D printing technology, enabling the creation of customized bone replacements tailored to individual needs. CT scan of the tibia where the 13 fracture is clearly visible.  CT - Scout A CT scout, AKA topogram, scanogram, or CT localizer radiograph, is a 2D X-ray image that helps position a patient for a CT scan: Purpose - used to define the scan range for a CT scan and help position the patient so that the correct anatomic structures are imaged. Axial View of the Brain (Focal seizure in a 5 yr old) 14  CT Scan - Window CT scans can also be "windowed" in a way that optimizes the visibility of different types of pathology after they are obtained Post-processing allows for additional manipulation of the raw data to best demonstrate the abnormality without repeating a study and re-exposing the patient. 2 yr old Lakshmi before doctors performed surgery on her in India. 15  CT - Indications C-Sp - Subtle misalignment of Trauma posterior facet joints at C6-7 with Suspected Intracranial hemorrhage mild foraminal narrowing Abdominal injury or pain Spine alignment Fracture detection and evaluation Tumor staging 2 different patients; Determining if a tumor A – oblique plain film; B – Sagittal CT; has transfissural growth C – post op x-ray lateral view 16 Magnetic Resonance Imaging - MRI Another imaging method for displaying anatomy in the axial, sagittal, and coronal planes. Patient is exposed to external magnetic fields and radio frequency waves. Advantage of MRI is ability to detect small changes within SOFT TISSUE 66 yr old after mva R frontal intraparanchymal hemorrhage. T1 and T2 Left is T1 flare Right is T2 17 MRI - Scout 18 Magnet that uses the body’s H ions 19  MRI – Concerns Magnetism Noise Must be still No pregnancy Gadolinium - No known biological hazards and the contrast has low incidence of side effects. 20 MRI - Contraindications Pregnancy unless emergency Cerebral aneurysms clipped by ferromagnetic clips. “nonferromagnetic” or “weakly” are acceptable – stainless steel or titanium Cardiac pacemakers Inner ear implants Metallic foreign bodies in and around eyes 21 MRI – T1 versus T2 Sequences  Appearance of fluid: On a T1 image, fluid (like cerebrospinal fluid) appears dark, whereas on a T2 image, fluid appears bright.  Best for visualizing: T1 is better for viewing normal anatomy and fat distribution, while T2 is better for identifying abnormalities like edema, tumors, or inflammation. Signal intensity of fat: Fat appears bright on a T1 image and relatively dark on a T2 image. Mnemonic: – Think "T1 - Tissue" - highlighting normal tissue structure. – Think "T2 - Tumor" - often used to identify abnormal tissue like tumors. https://www.youtube.com/watch?v=UKLvLsK36qo 22 MRI – T1 versus T2 Sequences T1 T2 23 Ultrasonography – U/S Doppler Is fast, safe ,painless, and inexpensive compared to other modalities. Does not use x-rays or radiation Produces sectional anatomical planes These images are viewed on a monitor in real time, static images may be produced on film by a format camera 3 types: Sonogram (2D or 3D) & Doppler 2D Developing fetus (~12 wks) 3D 24  Ultrasonography – U/S pressure ulcer Echogenic (hyperechoic) – bright or white Sonolucent (hypoechoic or anechoic) – dark or black 25  Ultrasonography – U/S 1. Transducer probe receives waves 2. CPU calculates 3. Transducer pulse controls – change in amplitude, frequency, and duration of pulses emitted. 4. Display 5. Disk storage device 6. Printer 26  Ultrasonography Indications: Concerns Obstetrics With increased u/s = Pediatric brain decreased birth wgt Testicle and prostate Possibly due to Female breast and – Direct heat locally pelvis – Bubble (cavitation) – Chest for pleural fluid dissolved gases come out Abdomen of soln due to local heat Vascular disease There are no substantial ill effects but only use if necessary. 27  Nuclear medicine scans Types: Scintigraphy, SPECT, and PET scan. Indications: Used to diagnose, stage, and monitor disease. 28  Nuclear Imaging Studies - Scintigraphy Gamma cameras to detect internal radiation. Radioisotopes (tracers), like technetium-99m or iodine-131 Assess organ function and identify abnormalities by tracing the distribution of the Thyroid Scan radioisotope within the ↓absorption – dark/"cold" spot - ↓ body. blood supply bone Types: Bone scan, ↑absorption – bright or "hot" spot Thyroid scan, Liver scan 29 Nuclear Imaging Studies - Scintigraphy Bone Scan normal ↑ Prostate ca, ↑ whole-body met to spine. 30  Nuclear Imaging Studies – using CT PET (Positron Emission SPECT – Single Photon Tomography) –Sensitive for Emission Computed Cancer. Tomography. Decreased resolution. Good for bleeding, bone, gallbladder https://www.sciencedirect.com/science/article/pii/S1319016422003127 https://www.hopkinsmedicine.org/health/treatment-tests-and-therapies/nuclear-medicine#:~:text=Nuclear%20medicine%20is%20a 31 %20specialized,combination%20of%20many%20different%20disciplines.  Interventional Radiology the use of medical imaging techniques to guide doctors as they diagnose and treat certain problems with blood vessels and lymph vessels throughout the body. IR is also called image-guided therapy. – Angiography – Stenting – Embolization – Biopsy – Abscess drainage – Foreign body retrieval https://www.youtube.com/watch?v=WDjXyzQZTjo 32  Ordering a Study Key points to remember when ordering an imaging study: Clinical justification: clinical reason Patient information: patient's details Imaging modality selection: most appropriate. Specific instructions: Provide detailed instructions regarding the body part to be imaged, positioning, contrast administration (if needed), and any necessary preparation steps for the patient. Consult guidelines: Refer to established guidelines like the American College of Radiology (ACR) appropriateness criteria to ensure the imaging study is clinically indicated. 33 Approach to reading any image Identification Date of study Study ordered Body part Positioning Penetration (Exposure) Contrast Artifacts 34  Identification Name ID number DOB (date of birth) 35  Date of study and Study ordered AP View Date – Today or previous – Compare to previous Study – Correct study – Correct view PA (posterior to anterior) AP (anterior to posterior) Lateral 36  Study ordered – Views PA View 37 Study ordered 38 Which chest x-ray is AP and which one is PA? 39  Body part Body Part – Correct side 40  Positioning Positioning – Supine or upright non-rotated or neutral rotation – Rotation – Inspiration Left rotation 41  Penetration (Exposure) 5 Densities increasing brightness 42  Penetration (Exposure) The lower the density, the darker the object appears; decreased attenuation (blacker densities) - Such as AIR in the lungs and stomach. The higher the density, the lighter the object appears; increased attenuation (whiter densities) – Such as bone 43  Penetration (Exposure) Radiolucent or lucency: a darker area on the image as relatively more of the administered x-rays reaching the detector. Radiopaque or opacity: a whiter area on the image due to absorption of the x-rays prior to reaching the detector. 44  Radiography And even more dense… And even lighter…. Metal 45 46 47  Penetration Under Better 48 Contrast When is IV contrast required? Contrast agents: – Angiography – Iodine – Chest (malignant lesions) – Barium – All abdominal work for liver, – Barium sulfate pancreas, kidney, bladder) – Gastrofin 49 Contrast 4 Delivery Methods – IV – blood vessels, organs (brain, spine, liver, kidney) – Oral – GI organs (fast; used for constipation) – Rectal – large intestine and lower GI (large intestine and lower GI; like fleets enema) – Inhalation – lung and brain (rare, uncommon, example is xenon gas) 50  CT – Contrast Enhanced Takayasu’s arteritis 30 yr old female cramping abdominal pain that readiated to the back – thickening of aortic ball on both images. 51  Artifacts Unwanted, unexpected, and often misleading features or structures that appear on X-ray images. https://radiologykey.com/radiographic-artifacts/ Movement Artifact Breast Implants 52  Artifacts Acupuncture Needles Penile Implant 53  References 1 Clinical Radiology Made Ridiculously Simple, Hougue Ouellette, MD, Patrice Tetreault, MD, Second Edition (not in Barry library. Can be purchased for $10; New for $30.95) 2 Radiology Masterclass – free tutorials https://www.radiologymasterclass.co.uk/tutorials/tutorials 3 Basics of Radiology, Heřman, Miroslavet al. (Barry library) https://eds.p.ebscohost.com/eds/ebookviewer/ebook/ZTAwMHhuYV 9fMzE3NzAwN19fQU41?sid=6f3abe64-8c91-41ae-8aee-5a81004c8 a33@redis&vid=1&format=EB 54 The End 55