Radiology Artifacts Screen-Film Mammography http://www.sma.org.sg/smj/4707/4707pe1.pdf Screen-Film Mammography Pressure mark or crimp mark due to excessive pressure on film appears as increased optical density. Screen-Film Mammography http://www.sma.org.sg/smj/4707/4707pe1.pdf Screen-Film Mammography Artifacts caused by dust and dirt on intensifying screen creating white spots simulating calcifications Screen-Film Mammography http://www.sma.org.sg/smj/4707/4707pe1.pdf Screen-Film Mammography Blurring due to motion Screen-Film Mammography http://www.sma.org.sg/smj/4707/4707pe1.pdf Screen-Film Mammography Fingerprints Screen-Film Mammography http://www.sma.org.sg/smj/4707/4707pe1.pdf Screen-Film Mammography Long streak of stain on intensifying screen appearing as minus density Screen-Film Mammography Obvious underexposure but not caused by technique or processing http://www.sma.org.sg/smj/4707/4707pe1.pdf Screen-Film Mammography Two films loaded into same cassette Screen-Film Mammography http://www.sma.org.sg/smj/4707/4707pe1.pdf Screen-Film Mammography Wet or damp screen causing plus density Screen-Film Mammography Easy one. Why is ID superimposed on breast? http://www.sma.org.sg/smj/4707/4707pe1.pdf Screen-Film Mammography Cassette loaded backwards (frontback) into bucky tray. Screen-Film Mammography Obvious underexposure but not caused by technique or processing http://www.sma.org.sg/smj/4707/4707pe1.pdf Screen-Film Mammography Film loaded upside down into cassette Screen-Film Mammography Easy? http://www.sma.org.sg/smj/4707/4707pe1.pdf Screen-Film Mammography Cassette loaded upside down into bucky tray. Screen-Film Mammography http://www.sma.org.sg/smj/4707/4707pe1.pdf Screen-Film Mammography Light leak in cassette Incompletely latched crack Screen-Film Mammography http://www.sma.org.sg/smj/4707/4707pe1.pdf Screen-Film Mammography Double exposure Screen-Film Mammography http://www.sma.org.sg/smj/4707/4707pe1.pdf Screen-Film Mammography Compression paddle vertical section (anterior lip) Screen-Film Mammography http://www.sma.org.sg/smj/4707/4707pe1.pdf Screen-Film Mammography Films run through processor too close together (overlapped) Screen-Film Mammography http://www.sma.org.sg/smj/4707/4707pe1.pdf Screen-Film Mammography Static electricity Screen-Film Mammography http://www.sma.org.sg/smj/4707/4707pe1.pdf Screen-Film Mammography Emulsion pick-off caused by pulling stuck films apart Screen-Film Mammography http://www.sma.org.sg/smj/4707/4707pe1.pdf Screen-Film Mammography Black arrows point at vertical black lines perpendicular to direction of film travel through processor. Cause: pressure from developer roller or moisture on entrance roller. Screen-Film Mammography http://www.sma.org.sg/smj/4707/4707pe1.pdf Screen-Film Mammography Dust in darkroom and dirty rollers causing emulsion pick-off. Screen-Film Mammography http://www.sma.org.sg/smj/4707/4707pe1.pdf Screen-Film Mammography Over-development caused by chemical fog. Radiography Two images of same anatomy. What changed? http://radiographics.rsnajnls.org/cgi/reprint/11/2/307?maxtoshow=&HITS=10 &hits=10&RESULTFORMAT=&fulltext=grid+artifacts&andorexactfulltext=an d&searchid=1&FIRSTINDEX=0&sortspec=relevance&resourcetype=HWCIT Radiography No grid 102 cm SID .33R ESE Grid 122 cm SID 2.2 R ESE CR What are white spots? http://radiographics.rsnajnls.org/cgi/reprint/11/5/795?maxtoshow=& HITS=10&hits=10&RESULTFORMAT=&fulltext=artifact&searchid=1 &FIRSTINDEX=10&sortspec=relevance&resourcetype=HWCIT CR Dust / dirt on phosphor screen CR Dirt on CR plate. Right image repeated on screen-film http://radiographics.rsnajnls.org/cgi/reprint/11/5/795?maxtoshow=& HITS=10&hits=10&RESULTFORMAT=&fulltext=artifact&searchid=1 &FIRSTINDEX=10&sortspec=relevance&resourcetype=HWCIT Rot at ing Mir r or PM Tube Light Laser Analog/ Digit al Comput er Beam scanned across film Plate Travel CR What are white lines? http://radiographics.rsnajnls.org/cgi/reprint/11/5/795?maxtoshow=& HITS=10&hits=10&RESULTFORMAT=&fulltext=artifact&searchid=1 &FIRSTINDEX=10&sortspec=relevance&resourcetype=HWCIT CR Cracks on image plate due to mechanical wear CR http://radiographics.rsnajnls.org/cgi/reprint/11/5/795?maxtoshow=& HITS=10&hits=10&RESULTFORMAT=&fulltext=artifact&searchid=1 &FIRSTINDEX=10&sortspec=relevance&resourcetype=HWCIT CR Transport problems in CR reader Rotating Mirror PMTube Light Laser Analog/ Digital Computer Beam scanned across film Plate Travel CR What are funny dark patterns on ventilator tube metal stabilizer? http://radiographics.rsnajnls.org/cgi/reprint/11/5/795?maxtoshow=& HITS=10&hits=10&RESULTFORMAT=&fulltext=artifact&searchid=1 &FIRSTINDEX=10&sortspec=relevance&resourcetype=HWCIT CR Moire effect because of interference between scan frequency of matrix and spiral CR http://radiographics.rsnajnls.org/cgi/reprint/11/5/795?maxtoshow=& HITS=10&hits=10&RESULTFORMAT=&fulltext=artifact&searchid=1 &FIRSTINDEX=10&sortspec=relevance&resourcetype=HWCIT CR Diagonal collimation caused algorithm to improperly recognize collimated area CR http://radiographics.rsnajnls.org/cgi/reprint/11/5/795?maxtoshow=& HITS=10&hits=10&RESULTFORMAT=&fulltext=artifact&searchid=1 &FIRSTINDEX=10&sortspec=relevance&resourcetype=HWCIT CR Chest incorrectly specified by technologist to CR reader as lumbar spine Ultrasound There’s flow but it isn’t showing up. Why? http://radiographics.rsnajnls.org/cgi/reprint/12/1/35?maxtoshow=&HITS=10& hits=10&RESULTFORMAT=&fulltext=artifacts&andorexactfulltext=and&search id=1&FIRSTINDEX=0&sortspec=relevance&resourcetype=HWCIT Ultrasound Improper setting of velocity scale (set too high). Low flow not displayed http://radiographics.rsnajnls.org/cgi/reprint/12/1/35?maxtoshow=&HITS=10& hits=10&RESULTFORMAT=&fulltext=artifacts&andorexactfulltext=and&search id=1&FIRSTINDEX=0&sortspec=relevance&resourcetype=HWCIT Ultrasound What’s that funny reversed flow? http://radiographics.rsnajnls.org/cgi/reprint/12/1/35?maxtoshow=&HITS=10& hits=10&RESULTFORMAT=&fulltext=artifacts&andorexactfulltext=and&search id=1&FIRSTINDEX=0&sortspec=relevance&resourcetype=HWCIT Ultrasound Improper setting of velocity scale (set too low). Aliasing occurs Ultrasound Low flow in both directions? http://radiographics.rsnajnls.org/cgi/reprint/12/1/35?maxtoshow=&HITS=10& hits=10&RESULTFORMAT=&fulltext=artifacts&andorexactfulltext=and&search id=1&FIRSTINDEX=0&sortspec=relevance&resourcetype=HWCIT Ultrasound Doppler angle is 90o; sample volume has vessel perpendicular to beam. Right image alters Doppler angle. Ultrasound Same anatomy. Why is there spectral broadening on the left image? http://radiographics.rsnajnls.org/cgi/reprint/12/1/35?maxtoshow=&HITS=10& hits=10&RESULTFORMAT=&fulltext=artifacts&andorexactfulltext=and&search id=1&FIRSTINDEX=0&sortspec=relevance&resourcetype=HWCIT Ultrasound 71o Doppler angle 81o Doppler angle Minimize spectral broadening artifact by using Doppler angles < 60o