Y khoa - Dược - Chapter 50: Diagnostic imaging

50Diagnostic Imaging50.1 Explain what X-rays are and how they are used for diagnostic and therapeutic purposes. 50.2 Compare invasive and noninvasive diagnostic procedures. 50.3 Carry out the medical assistant’s role in  X-ray and diagnostic radiology testing. 50.4 Discuss common diagnostic imaging procedures. Learning Outcomes50.5 Describe different types of radiation therapy and how they are used.50.6 Explain the risks and safety precautions associated with radiology work. 50.7 Relate the advances in medical imaging to EHR.Learning OutcomesIntroductionDiagnostic radiologyScreening Clinical diagnosisMedical assistantRole during testingSafety issuesProper handling and storage of filmsPreparation and instruction of patientsBrief History of the X-Ray Discovered in 1895 by Wilhelm Konrad RoentgenX-ray High energy levelShort wavelengthBrief History of the X-Ray (cont.)Diagnostic and therapeutic usesRadiologic technologistsRadiologist Performs invasive proceduresInterprets filmsDiagnostic RadiologyUse of X-ray technology to diagnoseContrast mediumMakes internal organs denserProduces a clearer imageTypes Gases Heavy metal saltsParamagnetic compoundsIodine compoundsDiagnostic Radiology (cont.)Invasive proceduresA testing device is inserted into a blood vessel or organRequires surgical aseptic techniquePatients must be closely monitoredDiagnostic Radiology (cont.)Noninvasive proceduresView internal structuresUses the conventional x-ray machine or specialized instrumentsApply Your KnowledgeWhat is the difference in noninvasive and invasive procedures?ANSWER: Noninvasive procedures do not require inserting devices, breaking the skin, or special monitoring and use conventional x-ray machines or specialized instruments to visualize internal organs. Invasive procedures require surgical aseptic technique for the insertion of a catheter, wire, or other testing device into an organ or blood vessel.X-rays are __________________ waves that travel at the speed of light and penetrate solid objectselectromagneticRight!Medical Assistant’s Role in Diagnostic RadiologyAssist with or perform proceduresBased on scope of practice for statePre- and postprocedure carePatient educationMedical Assistant’s Role in Diagnostic Radiology (cont.)Preprocedure careSchedule appointmentsProvide preparation instructionsExplain the procedure Ask pertinent questionsMedication historyWomen – possibility of pregnancy Medical Assistant’s Role in Diagnostic Radiology (cont.)Care during and after a procedurePrepare and assist the patientAssist the radiologic technologist or radiologistPosteroanterior (back to front)Medical Assistant’s Role in Diagnostic Radiology (cont.)Verifying insurancePrior to testingObtain necessary referralsBe sure to schedule at a facility contracted with the patient’s health insuranceApply Your KnowledgeHow can you find out what role you can take in radiologic testing as a medical assistant?ANSWER: Check your scope of practice for the state you are working in.Very Good!Common Diagnostic Radiologic TestsCommon testsContrast media in diagnostic tests Administered orally, IV, by enemaAdverse effectsMild to severeLocalized to systemicCheck for allergy to iodine or shellfishMonitor patient for signs of allergyCommon Diagnostic Radiologic Tests (cont.)Fluoroscopy X-rays cause certain chemicals to emit visible lightAllows for viewing movement of an organ or a contrast medium through organsCommon Diagnostic Radiologic Tests (cont.)HysterosalpingographyExamination of uterus and fallopian tubes by fluoroscopyUsed to evaluate shape and structure of uterus and patency of fallopian tubesCommon Diagnostic Radiologic Tests (cont.)AngiographyInvasive procedure using a contrast mediumAssess arteries or veinsMedical assistantScheduleAnswer questionsCommon Diagnostic Radiologic Tests (cont.)Arthrography Contrast medium and fluoroscopyProvides an image during movementUsed to diagnose abnormalities or injuries in cartilage, tendons, or ligamentsCommon Diagnostic Radiologic Tests (cont.)Barium enema Contrast media Single-contrast – barium Double-contrast – barium and airDiagnose and evaluate the colon or rectum. Patient instructions and compliance importantCommon Diagnostic Radiologic Tests (cont.)Barium swallowContrast medium – bariumDiagnose and evaluate the esophagus, stomach, duodenum, and small intestinePatient instructions and compliance important Common Diagnostic Radiologic Tests (cont.)Cholecystography Oral contrast mediumDetect gallstones or abnormalities of the gallbladderCholangiography Contrast medium injected into common bile ductEvaluate function of bile ductCommon Diagnostic Radiologic Tests (cont.)Conventional tomography Uses a computerized camera that moves back and forth over the patientOne view per arc over patientComputer tomography Camera rotates completely around the patient Cross-sectional view from each rotationCommon Diagnostic Radiologic Tests (cont.)Heart X-ray Angiocardiography Contrast medium usedImages of medium flowing through the heart, lungs, and major vesselsCoronary arteriographyCommon Diagnostic Radiologic Tests (cont.)Intravenous pyelography (IVP) Contrast media is injected into a veinShows contrast medium moving through kidneys, ureters, and bladderRetrograde pyelography – similar to IVP but contrast medium injected through a urethral catheterCommon Diagnostic Radiologic Tests (cont.)KUB radiography X-ray of abdomenAssesses the size, shape, and position of urinary organsMagnetic resonance imaging (MRI) With or without contrast mediumExamines internal structures and soft tissuesCommon Diagnostic Radiologic Tests (cont.)Mammography X-ray exam of internal breast tissuesSpecially trained radiologic technologistMammotest Biopsy Procedure Stereotactic breast biopsyComputer guidedCommon Diagnostic Radiologic Tests (cont.)Myelography Fluoroscopy used to evaluate spinal abnormalitiesPerformed less frequently because of new technologyCommon Diagnostic Radiologic Tests (cont.)Nuclear medicine Use of radionuclides to evaluate internal organsTypes includeSPECTPETMUGA scanCommon Diagnostic Radiologic Tests (cont.)Ultrasound Directs high-frequency sound waves to produce an echo of the internal organEchoes are converted to an imageApply Your KnowledgeTrue or False:___ Fluoroscopy is used for many procedures. ___ Hysterosalpingography is used to evaluate the patency of the colon.___ Cholangiography is used to detect abnormalities of the gallbladder.___ For an IVP, the radiologist injects the contrast medium through a catheter.___ An MRI uses a combination of nonionizing radiation and a strong magnetic field.___ Myelography is done frequently to evaluate for spinal abnormalities.ANSWER:less often due to advanced technologiesFFFFTTa retrograde pyelographybile ductfallopian tubesCommon Therapeutic Uses of RadiationRadiation therapy – used to treat cancer by preventing cellular reproductionTeletherapy External beam radiotherapyAllows deep penetration of tissuesStereotactic radiosurgery – precise delivery of radiationCommon Therapeutic Uses of RadiationBrachytherapy Places temporary radioactive implants close to or directly into the cancerous tissueRequires special precautions for radiation safetyApply Your KnowledgeWhat are the two types of radiation therapy?ANSWER: Teletherapy allows for deep penetration and is used for deep tumors. Brachytherapy involves the implantation of temporary radioactive implants close to or directly into cancerous tissue.Superb!Radiation Safety and DosePatient exposure reducedAdvances in technologyAssessment of benefit-to-risk ratio NCRP goals Prevent serious damage from radiation by limiting radiation dose levelsReduce risk of cancer and genetic effectsRadiation Safety and Dose (cont.)Personnel safetyWear a radiation exposure badgeMake sure equipment is working properlyUse lead shields as appropriate Patient safetyStoring and Filing X-raysKeep fresh film on hand Keep at proper temperature and humidityPrevent pressure marks Keep expiration dates visibleStoring and Filing X-raysUse oldest film firstOpen all packages or boxes in darkroomDo not store near acid or ammonia vaporsApply Your KnowledgeWhat should the physician consider before ordering radiologic testing for a patient?ANSWER: The benefit-to-risk ratio.Great!How do you store new and exposed x-ray film?ANSWER: X-ray film should be stored at proper temperature and humidity. Packages should be stored on end and not stacked.Electronic MedicineTelemedicine technologyRapid videoComputer-based communicationsUses includeViewing medical imagesConsults Transmission of data electronicallyElectronic MedicineDigital imaging and EHR Digital reader “captures” imageAdvantages includeBetter image qualityFaster resultsDecreased radiation exposureElectronic MedicineDICOMStandard for handling, storing, and transmitting information in medical imagingPAC ~ digital storage areaAdvances in radiology – 3D/4D ultrasoundApply Your KnowledgeWhat is DICOM?ANSWER: DICOM is a communications protocol for handling, storing, printing, and transmitting information in medical imaging.Fantastic!In Summary50.1 An X-ray is a high-energy electromagnetic wave that travels at the speed of light and can penetrate solid objects. X-rays can be used for diagnosis by producing images of internal body structures. Therapeutically, X-rays are used to treat cancer by preventing cellular reproduction. In Summary50.2 Invasive procedures require a radiologist to insert a catheter, wire, or other testing device into a patient’s blood vessel or organ through the skin or a body orifice. Noninvasive diagnostic procedures do not require inserting devices, breaking the skin, or the degree of monitoring needed with invasive procedures. In Summary (cont.)50.3 A medical assistant can work directly with a radiology facility to assist the radiologist or technicians in performing diagnostic procedures. Providing preprocedure and postprocedure care are duties a medical assistant can perform in a medical or radiology facility. In Summary (cont.)50.4 Numerous diagnostic imaging procedures are used in medicine today including: angiography, fluoroscopy, MRI, CT, arthrography, IVP, KUB, mammography, upper and lower GI series, ultrasound, and cholangiography.In Summary (cont.)50.5 The two basic types of radiation therapy are teletherapy and brachytherapy. Teletherapy is also called external beam radiotherapy because an external beam of radiation is used to penetrate deep tumors. Brachytherapy uses temporary radioactive implants positioned close to or directly into cancerous tissue to treat the tumor and spare healthy tissue.In Summary (cont.)50.6 The greatest risk associated with a radiology facility is the potential for radiation exposure to patients and healthcare workers. To eliminate this risk, certain safety precautions should be followed. These include careful evaluation by the physician to determine the medical necessity of radiology testing, avoiding X-rays altogether if a patient is pregnant, and requiring all personnel who work in a radiology facility to wear a dosimeter. In Summary (cont.)50.7 Major advances in telemedicine technology, including rapid video and computer-based communications of medical information, enable physicians to “examine” a patient in another city or country, view highly detailed medical images, consult with specialists in other cities, and supervise complex medical procedures. Sharing records including actual radiographic images between facilities is easier with the advent of digital radiographic procedures and the electronic health record.End of Chapter 50Words can be like X-rays if you use them properly--they'll go through anything. You read and you're pierced.” ~ Aldous Huxley