Introduction to Fluoroscopy & Radiation Safety RTEC 124 - Week 10 Rev 2010 References: Merrills CH 16 & 17 Bushong – Ch 21

CONVENTIONAL FLUOROSCOPY INVENTED BY THOMAS EDISON Early Fluoroscopy

Digital / Fluoro Equipment Check off MUST BE COMPLETED PRIOR TO DOING ANY PATIENT EXAMS Fluoroscopy Procedures must ALWAYS be supervised – even after a check off You MUST be a CRT to have a Fluoroscopy Lic to operated fluoro units in California (CDPH-RHB Title 17)

Fluoroscopy: Images in Motion Conventional & Digital Fluoro Principles Fluoroscopy is a common technique used by clinical physicians to obtain real time images of moving body parts and internal structures of a patient compared to static radiographic examinations.

Objectives Differentiate fluoroscopic examinations from static diagnostic radiographic examinations Describe a typical basic fluoroscopic image chain (RT 244 – detailed) Explain difference between fluoroscopic operation and a diagnostic x-ray tube Safety Principles

Types of Equipment C-arm Under table/over table units Conventional & Digital Units

Recording the Fluoroscopic Image Cassettes 105 mm chip film Digital fluoroscopy Dynamic Systems Cine film (cardiac cath) Videotape (OPMS)

IMAGE INTENSIFICAITON photons are ampilfied + multiplied IMAGES ARE VIEWED ON A TV SCREEN/MONITOR

Image Intensifier & Cassette loading Digital & Conventional Units

Image Intensifier Bushong – Ch 21

Important to limit the field of view (collimation)

X-ray tube located under the table Conventional Fluoro X-ray tube located under the table

X-ray tube located under or over the table – remote controls DIGITAL FLUORO X-ray tube located under or over the table – remote controls

The Role of the Technologist Provide Assistance To the Patient And Radiologist Before, during and after the procedure Prep the room Prep the contrast Prep the patient Get a history from the patient Aftercare instructions and clean up of supplies

GU studies GI tract studies Carlton – Ch. 40 Fluoroscopic Uses Functional studies – xrays in motion GI tract studies Esophagus /OPMS Upper GI SMB BE ERCP GU studies - VCU's, RT 255 The “OGRAMS” Angiograms Hysterosalpingograms Venogram Myelogram Sialogram Tube /Line placement Fistulograms ETC ETC PAIN CLINIC (C-ARM)

Radiation Safety and Fluoroscopy Time Distance Shielding The Patient & Scatter

Radiation Protection During Fluoroscopy The patient The radiographer and radiologist Others

RADIATION PROTECTION The Patient is the largest scattering object Lower at a 90 DEGREE ANGLE from the patient + PRIMARY BEAM AT 1 METER DISTANCE - 1/1000 OF INTENSITY PRIMARY XRAY or 0.1%

Room design Remember to move the overhead tube out of the way!

Protective Barriers Primary barrier – protection from Primary radiation (for the patient& technologist ) The II is a 2.0 mm pb eq barrier Secondary barrier - protection from Secondary radiation (from the patient) - Protection for the technologists, etc

Iso Exposure Curves Where is it SAFE?? Behind the lead shield and behind the Radiologist! Behind the lead shield and behind the Radiologist!

Minimum source-to-skin distance Patient entrance skin exposure (ESE) is higher when the fluoroscopic x-ray tube is too close to the tabletop. Minimum source-to-skin distance 12” for mobile equipment 15” for stationary systems Audible alarm at 5 mins. Same rules for collimation

KEEP I.I. CLOSE TO PATIENT PATIENT EXPOSURE KEEP I.I. CLOSE TO PATIENT REDUCE DISTANCE OF IMAGE INTESIFIER INCREASE DISTANCE FROM THE TUBE Patient entrance skin exposure (ESE) is ALSO higher when the IMAGE INTENSIFIER is too FAR to from the patient.

Over vs Under the table fluoro tubes & Scatter

Under table tube vs Over table tube (remote units) Digital & Conventional Fluoro

Fluoroscopic X-Ray Tubes mA range: 0.5 – 5.0 mA KVP: 70 – 110 depending on exam and contrast used 15” minimum SOD in fixed fluoroscopic equipment Foot switch (dead man)

IsoExposure Curves Where is it SAFE?? VCUG

Fluoroscopic Positioning Previewing Radiographers are trained in positioning Unnecessary radiation exposure to patient is unethical Fluoroscopic equipment should not be used to preview patient’s position

Principles of Personnel Exposure Reduction Time Distance Shielding Protective barriers Protective devices

Important to keep the curtain in place

Protection of Radiographer and Radiologist Lead apron 0.25 mm Pb/eq Highest energy scatter Same level as radiographer /radiologist’s gonads (135o under table) OR for eyes (over table 45o) see diagrams 90o angle to the incident beam (lowest) (without shield – still high see isoexposure curves)

Protection of Radiographer and Radiologist Used when it is not possible to remain behind a barrier Lead aprons Lead gloves Lead glasses Thyroid shields 0.25 –1.0 mm lead eq Protection of Radiographer and Radiologist Single step away from the table decreases exposure exponentially (inverse sq law) Bucky slot cover Lead rubber drape Radiologist as shielding

Shielding TECHNOLOGIST .25 MM LEAD APRON THYROID SHEILD PATIENT – WHEN NOT IN AREA OF INTEREST REMEMBER WHERE THE SOURCE OF THE XRAY BEAM IS COMING FROM! .5MM FOR GONADS What is the pb eq? Can this be used for gonads?

WHATS WRONG?

Tabletop exposure rate Maximum 10 R/min Typically 1 – 3 R/min Patient Protection Tabletop exposure rate Maximum 10 R/min Typically 1 – 3 R/min Typical exposure rates Cinefluorography 7.2 R/min Cassettes 30 mR/exposure 105 mm film 10 mR/exposure

ALARA: As Low As Reasonably Achievable Radiologic personnel are responsible for minimizing radiation exposure to patients Achieved through thoughtful approach and application of radiation protection practices Procedure dose to patient

Protection of Others Radiographer’s responsibility to inform others in the room to wear lead apron Do not initiate fluoroscopy until all persons have complied

Protection of Personnel during FLUOROSCOPY Radiologic personnel should not hold patients for exposures Student SHALL not hold patient during radiation exposure Family or friend better choice Immobilization devices best choice

Bucky Slot Cover

TABLE MOVEMENT

Always make sure the foot Board is correctly in place BEFORE standing a pt on the table Check weight limit for table

BASIC PROCEDURES For FLUOROSCOPY Note – do not allow pt to place Cup on the II - Table will move from vertical to horizontal!

Depending on the study – the patient may begin in the upright position The Radiologist may then place the patient and table recumbant to finish the fluoro study Depending on the study – the patient may begin in the upright position The Radiologist may then place the patient and table recumbant to finish the fluoro study

OVERHEADS taken after DR leaves room Depending on the study – the patient may begin in the upright position The Radiologist may then place the patient and table recumbant to finish the fluoro study OVERHEADS taken after DR leaves room

“OVERHEADS” AFTER FLUOROSCOPY IS COMPLETE LARGER FORMAT IMAGE 14X17 DIGITAL 14X14 MAX

Enteroclysis procedure (SMB)

Single contrast Double Contrast

PROCEDURE???

Problem ? Pathology? DO NOT give Barium to this Patient……. Why Not? Will cover with contrast media lecture