DSA versus Cine Runs: Minimizing radiation exposure

DSA versus Cine Runs:Minimizing Radiation ExposureRobert M. WeinsteinMay 2012DSA vs. Cine Runs:Minimizing radiation exposure 1

Objectives• Have an understanding of DSA and cineangiography and their differences.• Have an understanding of the advantages ofDSA over cine angiography.• Be able to understand and utilize all theadvantages that DSA offers.DSA vs. Cine Runs:Minimizing radiation exposure2

DSAorCine Angiography• What is Angiography?• Angiography or arteriography is a medicalimaging technique in which an X-ray picture istaken to visualize the inner opening (lumen) ofblood filled structures, including arteries, veinsand the heart chambers. Its name comes from theGreek words angeion, "vessel", and graphien, "towrite or record". The X-ray film or image of theblood vessels is called an angiograph, or morecommonly, an angiogram.DSA vs. Cine Runs:Minimizing radiation exposure3

DSAorCine AngiographyWhich was first for filming angiograms?Neither!• Conventional subtraction angiography came before cinefilming and was the frontrunner to DSA.• Subtraction angiography was mostly used for neuroangiography.• Subtraction angiography was a long, tedious and timeconsuming procedure.• Subtraction angiography was not fun!!DSA vs. Cine Runs:Minimizing radiation exposure4

What is SubtractionAngiography?• Subtraction angiography was a way tovisualize arteries by “masking” out boneydetails.• Equipment needed for SA:• Subtraction film• Masking film• Cut Film with a rapid film exchanger• Darkroom• Technologists with lots of time and patience!DSA vs. Cine Runs:Minimizing radiation exposure5

Puck RapidFilm ChangerDSA vs. Cine Runs:Minimizing radiation exposure6

STARTBring patient in roomLoad Rapid FilmChanger (Puck)Take Scout FilmDevelop Scout FilmMake a Maskof Scout Filmusing Masking FilmGo back to room totake series x-raysSubtractionFlowchartYesDid patient move?NoTake all cut film backto the darkroom anddevelopNeuro used APand Lat filmchangers andusually had over50 films!Choose the cut films forsubtraction.Go back to the darkroomand using the MASK andsubtraction film, make yourfinal subtraction study.Continue angioprocedure.Take series x-raysNoRadiologistpleased?YesDSA vs. Cine Runs:Minimizing radiation exposureSay someprofanitiesDONE7

What is Cine Angiography?• With the advent of cardiaccatheterization, physicians needed away to document and record theprocedure in a “live” format.• Conventional filming and conventionalsubtraction was not an option becauseof the constant heart movement.• Videotape was not a good optionbecause the image was not very sharp.DSA vs. Cine Runs:Minimizing radiation exposure8

What is Cine Angiography?• Radiologist wasoriginally in room withcardiologist to assist inthe procedure.• Cine film (35mm) wasused to documentcoronary angiogramsbecause it produced asharp, archival medium.DSA vs. Cine Runs:Minimizing radiation exposure9

Equipment needed forCine AngiogramCine equipped image intensifier.DSA vs. Cine Runs:Minimizing radiation exposure10

Equipment needed forCine AngiogramCine Roll FilmCine equipped image intensifierSplicerViewer/ProjectorDSA vs. Cine Runs:Minimizing radiation exposure11

Equipment needed forCine AngiogramCine Film ProcessorDSA vs. Cine Runs:Minimizing radiation exposure12

Equipment needed forCine Angiogram…and lots andlots and lots ofstorage!!DSA vs. Cine Runs:Minimizing radiation exposure13

Cine Angiography• Cine angiography today is commonlya misnomer for Digital Radiography.• Has become obsolete with the adventof Digital Radiography.• However, there is still some good usefor the old equipment.DSA vs. Cine Runs:Minimizing radiation exposure14

DSA versus DRDSA--Digital Subtraction Angiography• Less contrast is needed per injection.• Allows for lower frame rate usage.• Smaller vessels are better visualized.• Increased subtraction artifacts frompatient motion.DSA vs. Cine Runs:Minimizing radiation exposure15

DSA versus DRDR---Digital Radiography (non- subtracted)• More contrast or a lower dilution strengthis generally needed per injection.• Usually needs a higher frame rate foracquisitions.• Poorer visibility of smaller vessels.• No subtraction artifacts from patientmotion.DSA vs. Cine Runs:Minimizing radiation exposure16

DSA versus DRAdvantages of Digital Imaging1. Allows for lower patient dose.• LIH (last image hold) during fluoro.• Digital zoom and pan.• Contrast and edge enhancement for bettervisualization.• Collimation and filtering without fluoro ispossible with use of icons (Siemens).• CARE positioning (Siemens).DSA vs. Cine Runs:Minimizing radiation exposure17

DSA versus DRAdvantages of Digital Imaging2. Allows for image manipulation.• Peak opacification—DSA & DR• Bone landmarking—DSA• Pixel shifting—DSA• Re-masking—DSA• Image overlay (DSA) and road-mapping• Vessel analysis (DSA and DR)DSA vs. Cine Runs:Minimizing radiation exposure18

DSA AdvantagesPeak OpacificationDSA vs. Cine Runs:Minimizing radiation exposure19

DSA AdvantagesPeak OpacificationDSA vs. Cine Runs:Minimizing radiation exposure20

DSA AdvantagesBone LandmarkingDSA vs. Cine Runs:Minimizing radiation exposure21

DSA AdvantagesBone LandmarkingDSA vs. Cine Runs:Minimizing radiation exposure22

Conclusions• Digital Subtracted Angiography• Computer generated mask.• Subtracted runs acquired automatically.• Multiple manipulations of acquired runs.• Lower acquisition frame rate for lower patient dose.• Digital Radiography• No subtraction artifacts from patient movement.• Higher frame rates.• Uses digital imaging for acquisitions and playbackand image manipulation.DSA vs. Cine Runs:Minimizing radiation exposure23